Research ArticleA Novel Miniaturized Dual Slant-PolarizedUWB Antenna Array with Excellent Pattern SymmetryProperty for MIMO Applications

Zhi Zeng1 Jianjun Huang2 Zhaohui Song3 and Qinyu Zhang1

1Shenzhen Graduate School Harbin Institute of Technology Shenzhen 518055 China2MOBI Antenna Technologies (Shenzhen) Co Ltd Shenzhen 518057 China3Harbin Institute of Technology Harbin 150001 China

Correspondence should be addressed to Qinyu Zhang zqyhiteducn

Received 30 June 2014 Accepted 4 September 2014

Academic Editor Wenhua Chen

Copyright copy 2015 Zhi Zeng et alThis is an open access article distributed under the Creative CommonsAttribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

A novel miniaturized 1 times 10 uniform linear dual slant-polarized UWB antenna array for MIMO base station is presented Theantenna array operates in the frequency band from 1710 to 2690MHz with a 173ndash187 dBi gain in a size of 105 times 1100 times 37mmThearray element is composed of two single-polarized dipoles evolved from bow-tie antenna with slots on them which miniaturizethe size of the antenna The 10 array elements are fed through an air dielectric strip-line power splitter Two parameters the beamtracking and the beam squint are presented to quantitatively describe the pattern symmetry property of the antennaThe simulatedandmeasured radiation performances are studied and comparedThe results show that the pattern symmetry property of the singleantenna element has been improved about 24 compared with the former study and the antenna array also provides excellentpattern symmetry property

1 Introduction

Multiple-input multiple-output (MIMO) is the use of mul-tiple antennas at both the transmitter and the receiver toimprove communication performance [1] MIMO has attra-cted attention in wireless communications because it offerssignificant increases in data throughput and link range with-out additional bandwidth or increased transmit power [2] Itachieves this goal by spreading the same total transmit powerover the antennas to achieve an array gain that improvesthe spectral efficiency andor to achieve a diversity gain thatimproves the link reliability (reduced fading) [3] Becauseof these advantages MIMO is an important part of modernwireless communication standards such as IEEE 80211n (WI-Fi) 4G 3GPP Long Term Evolution (LTE) WiMAX andHSPA+ [4] While coding and signal processing are keyelements to successful implementation of a MIMO systemthe propagation channel and the antenna design representmajor parameters that ultimately impact the system perfor-mance As a result considerable research has been devoted

recently to these two areas For example assessing the poten-tial of MIMO systems requires a new level of understandingconcerning multipath channel characteristics Furthermorewhile we have extensive information concerning the behaviorof an antenna in multipath channels [5] recent activitysurroundingMIMOcommunications has exposed new issuesrelated to the impact of antenna properties and the arrayconfiguration on the systemperformance In [6] a simulationstudy of the channel capacity of a MIMO antenna systemexploiting multiple polarizations was carried out while in [7]Perez and Ibanez analyzed the capacity of MIMO systemsbased on dual-polarized antenna array

In modern mobile telecommunications industry dualslant-polarized (+45∘minus45∘) base station antennas are widelyused for their good anti-multi-path property Usually in a 2Gnetwork a dual slant-polarized base station antenna works in1T2Rmode (1 of the 2 channels for transmitting both 2 chan-nels for receiving) In 3G or LTE network both 2 channels ofthe dual slant-polarized base station antennamight be used totransmit and receive the signal In this case highly symmetric

Hindawi Publishing CorporationInternational Journal of Antennas and PropagationVolume 2015 Article ID 801638 9 pageshttpdxdoiorg1011552015801638

2 International Journal of Antennas and Propagation

0

minus5

minus10

minus15

minus20minus180 0 180

Beam squint

Peak point

Beam

trac

king

minus45

+45

Figure 1 Antenna beam tracking and antenna beam squint

radiation patterns are required to the dual slant-polarizedbase station antenna However only a few studies about theradiation pattern symmetry of the antenna were carried outin the past In [8] Chair et al studied 4 different types ofdual-polarized dielectric resonator antennas and analyzedtheir radiation pattern symmetry qualitatively In [9] Gao etal presented a CPW-fed dual-polarized dielectric resonatorantenna with ldquoalmost symmetricalrdquo radiation patterns In[10] Mak and Rowell presented a dual-polarized patchantenna with symmetrical patterns for base station in 1710ndash2690MHz but they did not analyze the pattern symmetryquantitatively either In [11] Kim et al proposed a modifieddual-polarization horn antenna to improve radiation patternsymmetry and presented a method to evaluate the radiationpattern symmetryThey quantitatively analyzed the radiationpattern symmetry by comparing the normalized radiationpattern level of the EH-plane at some specified anglesincluding the minus10 dB beam width point The smaller the dif-ferences the better the radiation pattern symmetry Both thesimulated andmeasured results have shown that the radiationpattern level differences increase as the angle increases withinthe minus10 dB beam width range so the difference at minus10 dBbeam width point can be considered as a characteristic todescribe the radiation pattern symmetry In this paper it iscalled the beam tracking which is defined as the maximumlevel difference between the two orthogonal polarizationsnormalized radiation patterns at the 10 dB beam width pointas shown in Figure 1 The beam tracking can be expressedas

Beam tracking = max (1003816100381610038161003816119871minus119871minus 119871+119871

10038161003816100381610038161003816100381610038161003816119871minus119877minus 119871+119877

1003816100381610038161003816) (1)

where 119871minus119871

is the level of minus45∘ polarization at the 10 dB pointon the left 119871

+119871is the level of +45∘ polarization at the 10 dB

point on the left 119871minus119877

is the level of minus45∘ polarization atthe 10 dB point on the right and 119871

+119877is the level of +45∘

polarization at the 10 dB point on the right The smaller thebeam tracking is the better the symmetry of the radiation

pattern is Ideally the value of beam tracking is expected tobe 0 which means that the two patterns coincide completelyat the 10 dB point In [11] the authors supposed that theboresight was the axis of symmetry of the antenna Howeverfor most antennas the boresight is not the symmetry axisof the antenna because the beam is always tilted to oneside more or less In this case only the amplitude is notenough to describe the radiation pattern symmetry but alsothe angular dimension the beam squint The beam squint isdefined as the ratio of the boresight angle to the 10 dB beamwidth

Beam squint =boresight angle10 dB beam width

(2)

Ideally the value of beam squint is expected to be 0 whichmeans that the boresight is just the symmetry axis of theantenna The beam tracking and the beam squint describethe symmetric property of the dual-polarized antenna in theamplitude domain and the angular domain respectively

In this paper a novel compact 1 times 10 dual slant-polarizedantenna array with excellent pattern symmetry propertyis presented The proposed antenna array operates in thefrequency band from 1710 to 2690MHz with a size of 105times 1300 times 37mm The fractional bandwidth of the antennaarray is 445 which could be classified as ultra wideband(UWB) antenna according to the definition of UWB antennaby the Federal Communications Commission (FCC) andthe International Telecommunication Union Radio (ITU-R)[12] The simulations of the proposed antenna are performedusing the commercial electromagnetic simulation softwareHFSS In the whole range of 10 dB beam width the worstbeam tracking of the array element is 040 dB which hasbeen improved about 24 compared with the result as05398 dB in [11] And the beam squint values are betterthan 1 The antenna array also provides excellent patternsymmetry property A prototype of the proposed antennaarray was fabricated and measured in an anechoic chamberThe experimental measurements concerning the antennaparameters are found to be in good agreement with thenumerical results

2 Antenna Array Structure and Design

21 Antenna Array Element The pattern symmetry propertyof the antenna array is mainly decided by the propertiesof the array element so the design of the array element isquite importantThe geometry of the proposed antenna arrayelement is shown in Figure 2 The dual slant-polarized arrayelement is composed of 2 evolved bow-tie antennas on a105mm wide reflector and the total height is 37mm Theevolutionary process from bow-tie antenna to the proposedarray element is shown in Figure 3 The bow-tie antenna isa kind of antenna with two flaring triangular shaped armswhich is a typical wide band antenna [13] By adding sloton the arms the equivalent electrical length of the arms isincreased so as tominiaturize the dimensions of the antennaThe array element has a strictly symmetrical structure whichis expected to obtain good radiation symmetry property Thefeeding structure of the array element is shown in Figure 4

International Journal of Antennas and Propagation 3

(a) (b) (c)

Figure 2 The geometry of the array element (a) 3D view (b) top view (c) and side view

(a) (b) (c) (d)

Figure 3The evolution from bow-tie antenna to the proposed array element (a) bow-tie antenna (b) bow-tie antenna with slots (c) bow-tieantenna with slots and holes and (d) the proposed array element

(a) (b) (c)

Figure 4 The feeding structure of the dipole (a) 3D view (b) the feeding structure for minus45∘ and (c) the feeding structure for +45∘

By adjusting the shape and the dimensions of the innerconductor the antenna can be matched to 50Ω transmissionlines in a bandwidth of 1710MHzndash2690MHz Besides thatthere are some holes in the arms and some raised blocks atthe edge of the arms which are brought in to tune the returnloss over the whole frequency band

22 Antenna Array Based on the array element above a uni-form linear antenna array is designedThe proposed antenna

array is composed of 10 elements and the spacing betweenthe elements was set to 110mm based on the frequencycharacteristic The structure of the antenna array is shown inFigure 5 The antenna array is fed by two 1 to 10 air dielectricstrip-line power splitters which are connected with the 10elements through several coaxial cables as shown in Figure 6The air dielectric strip-line has quite low transmission losswhich contributes to the gain of the antenna The amplitudeof each dipole could be conveniently adjusted by adjusting

4 International Journal of Antennas and Propagation

110

mm

1100mm

110mm

Figure 5 The structure of the antenna array

To dipole 3

To dipole 4To dipole 5 To dipole 6

To dipole 7

To dipole 8To dipole 9

To dipole 10

To antenna port

To dipole 1

To dipole 2

Figure 6 The feeding structure of the antenna array

Table 1 The simulated beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 004 005 005 0062200 006 006 007 0072690 008 009 009 010

the impedance of the corresponding matching section andthe phase of each dipole could be adjusted by adjusting thecorresponding cable length The dimensions of the antennaarray are 105 times 1100 times 37mm

3 Antenna ArraySimulation and Measurement

A commercial electromagnetic simulation software HFSS isused to analyze the performance of the proposed antennaelement and the antenna array The weight of the amplitudeand the phase of each element were optimized to achieve alow upper side lobe level which is quite critical for a wirelesstelecommunication system base station The antenna arrayhas around 65 degrees beam-width inH-plane which is quitesuitable for base station of mobile communicationThe beamtracking and the beam squint of the array element and theantenna array are calculated in E-plane and H-plane Thesimulated results of the beam tracking are shown in Table 1The simulated beam squint results of the array element andthe antenna array are shown in Tables 2 and 3 respectivelyThe simulated results show that both the proposed antennaelement and the antenna array have quite good patternsymmetry property

Table 2 The simulated beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 035 030 038 0342200 048 053 049 0572690 053 058 060 058

Table 3 The simulated beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 035 032 039 0342200 050 055 049 0582690 056 059 061 060

A prototype of the proposed antenna array was fab-ricated for measurement The array elements were madeof aluminum for its good processing property and coatedwith Tin to prevent the surface oxidation The picture ofthe proposed antenna array prototype is shown in Figure 7while the numerical andmeasurement results concerning thefrequency behavior of the 119878 parameters of the antenna arereported in Figure 8

The measurement of radiation patterns was carried outin an enclosed anechoic chamber The simulated and themeasured radiation patterns in H-plane and E-plane areshown in Figures 9 and 10 respectively

The simulated and the measured gain curves of theproposed antenna array are shown in Figure 11 However themeasured gain data of the antenna is approximately 01 dBbelow the predicted values in the operation frequency bandThe reason for this behavior is probably coupling withinthe cable loss andor the nonideal power distribution of thepower dividers

International Journal of Antennas and Propagation 5

(a) (b)

(c)

Figure 7The photo of the proposed antenna array (a) top view of the array element (b) side view of the array element and (c) the proposedantenna array

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)

1710 1850 1990 2130 2270 2410 2550 2690

S22 simulatedS11 measuredS11 simulated

S22 measured

S11

andS22

(a)

1710 1850 1990 2130 2270 2410 2550 2690

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)S21 simulatedS21 measured

S21

(b)

Figure 8 The simulated and measured 119878 parameters of the proposed antenna array (a) |11987811

| and |11987822

| and (b) |11987821

|

The beam tracking and the beam squint of the arrayelement and antenna array are measured in E-plane and H-plane the measured results of the beam tracking are shownin Table 4 The measured beam squint results of the arrayelement and the antenna array are shown in Tables 5 and6 respectively The measured array element beam trackingresults are better than 040 dB which is about 24 betterthan the results as 05398 dB in [11] And the measuredantenna array beam tracking results are better than 041 dBBesides that all the measured results of the beam squintare better than 1 The measured data agree very well with

the numerical results and show attractive pattern symmetrycharacteristics for a MIMO base station

4 Conclusion

In this paper a novel compact 1 times 10 dual slant-polarizedantenna array with excellent pattern symmetry propertyhas been proposed The antenna array is composed of10 dual slant-polarized antenna array elements whichevolved from the bow-tie antennas The antenna arrayoperates in the frequency band 1710ndash2690MHz with a size

6 International Journal of Antennas and Propagation

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz minus45∘

(a)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz +45∘

(b)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz minus45∘

(c)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz +45∘

(d)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz minus45∘

(e)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz +45∘

(f)

Figure 9 The simulated and measured radiation patterns in H-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

International Journal of Antennas and Propagation 7

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz minus45∘

(a)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz +45∘

(b)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz minus45∘

(c)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz +45∘

(d)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz minus45∘

(e)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz +45∘

(f)

Figure 10 The simulated and measured radiation patterns in E-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

8 International Journal of Antennas and Propagation

1710 1850 1990 2130 2270 2410 2550 2690

170

175

180

185

190

Gai

n

Simulatedminus45 measured+45 measured

Frequency (MHz)

Figure 11 The gain of the proposed antenna array

Table 4Themeasured beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 026 026 027 0282200 036 036 037 0372690 040 041 040 040

Table 5 The measured beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 080 074 058 0552200 065 063 070 0672690 052 047 056 053

Table 6 The measured beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 082 075 069 0542200 071 069 072 0732690 066 051 060 061

of 105 lowast 1300 lowast 37mm only Two parameters the beamtracking and the beam squint that quantitatively describethe pattern symmetry were presented The results show thatthe pattern symmetry property of the single antenna elementhas been improved about 24 compared with the formerstudy and the antenna array also provides excellent patternsymmetry property

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to express their sincere gratitudeto MOBI Antenna Technologies (Shenzhen) Company forproviding the software package of HFSS and antenna testchamber This work was supported in part by the KeyProgram of the National Natural Science Foundation ofChina underGrant 61032003 and theNational Basic ResearchProgram of China under Grant 2009CB320402

References

[1] J F Valenzuela-Valdes M A Garcıa-Fernandez A MMartınez-Gonzalez and D A Sanchez-Hernandez ldquoEvalua-tion of true polarization diversity for MIMO systemsrdquo IEEETransactions on Antennas and Propagation vol 57 no 9 pp2746ndash2755 2009

[2] P-S Kildal and K Rosengren ldquoCorrelation and capacity ofMIMO systems and mutual coupling radiation efficiency anddiversity gain of their antennas simulations and measurementsin a reverberation chamberrdquo IEEE Communications Magazinevol 42 no 12 pp 104ndash112 2004

[3] K S Min D J Kim and M S Kim ldquoMulti-channel MIMOantenna design forWiBroPCS bandrdquo in Proceedings of the IEEEInternational Symposium on Antennas and Propagation Societypp 1225ndash1228 Honolulu Hawaii USA July 2007

[4] M A Jensen and J W Wallace ldquoA review of antennas andpropagation for MIMOwireless communicationsrdquo IEEE Trans-actions on Antennas and Propagation vol 52 no 11 pp 2810ndash2824 2004

[5] J Lee and N Jindal ldquoSymmetrie capacity of MIMO downlinkchannelsrdquo in Proceedings of the IEEE International Symposiumon Information Theory (ISIT rsquo06) pp 1031ndash1035 Seattle WashUSA July 2006

[6] L Dong H Choo R W Heath Jr and H Ling ldquoSimulationofMIMO channel capacity with antenna polarization diversityrdquoIEEE Transactions onWireless Communications vol 4 no 4 pp1869ndash1873 2005

[7] J Perez J Ibanez L Vielva and I Santamarıa ldquoCapacity esti-mation of polarization-diversity MIMO systems in Urbanmicrocellular environmentsrdquo in Proceedings of the 15th IEEEInternational Symposium on Personal Indoor and Mobile RadioCommunications (PIMRC rsquo04) vol 4 pp 2730ndash2734 September2004

[8] R Chair A A Kishk and K F Lee ldquoComparative study ondifferent feeding techniques for dual polarized dielectric reso-nator antennasrdquo in IEEE Antennas and Propagation SocietyInternational Symposium pp 2495ndash2498 Albuquerque NMUSA 2006

[9] Y Gao Z Feng and L Zhang ldquoCompact CPW-fed dielectricresonator antenna with dual polarizationrdquo IEEE Antennas andWireless Propagation Letters vol 10 pp 544ndash547 2011

[10] A C K Mak and C Rowell ldquoA low-cost dual-polarized wide-band antennardquo in Proceedings of the IEEE International Sym-posium on Antennas and Propagation Society pp 1478ndash1479Orlando Fla USA July 2013

International Journal of Antennas and Propagation 9

[11] J S Kim J H Yoon Y J Yoon W-S Lee and C-G KimldquoDesign of modified dual mode horn antenna to improve EH-plane radiation pattern symmetryrdquo in Proceedings of the 17thInternational Symposium on Antennas and Propagation (ISAPrsquo12) pp 547ndash550 Nagoys Japan November 2012

[12] F Gross Frontiers in Antennas Next Generation Design ampEngineering McGraw-Hill New York NY USA 2011

[13] E A Soliman S Brebels P Delmotte G A E Vandenboschand E Beyne ldquoBow-tie slot antenna fed by CPWrdquo ElectronicsLetters vol 35 no 7 pp 514ndash515 1999

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2 International Journal of Antennas and Propagation

0

minus5

minus10

minus15

minus20minus180 0 180

Beam squint

Peak point

Beam

trac

king

minus45

+45

Figure 1 Antenna beam tracking and antenna beam squint

radiation patterns are required to the dual slant-polarizedbase station antenna However only a few studies about theradiation pattern symmetry of the antenna were carried outin the past In [8] Chair et al studied 4 different types ofdual-polarized dielectric resonator antennas and analyzedtheir radiation pattern symmetry qualitatively In [9] Gao etal presented a CPW-fed dual-polarized dielectric resonatorantenna with ldquoalmost symmetricalrdquo radiation patterns In[10] Mak and Rowell presented a dual-polarized patchantenna with symmetrical patterns for base station in 1710ndash2690MHz but they did not analyze the pattern symmetryquantitatively either In [11] Kim et al proposed a modifieddual-polarization horn antenna to improve radiation patternsymmetry and presented a method to evaluate the radiationpattern symmetryThey quantitatively analyzed the radiationpattern symmetry by comparing the normalized radiationpattern level of the EH-plane at some specified anglesincluding the minus10 dB beam width point The smaller the dif-ferences the better the radiation pattern symmetry Both thesimulated andmeasured results have shown that the radiationpattern level differences increase as the angle increases withinthe minus10 dB beam width range so the difference at minus10 dBbeam width point can be considered as a characteristic todescribe the radiation pattern symmetry In this paper it iscalled the beam tracking which is defined as the maximumlevel difference between the two orthogonal polarizationsnormalized radiation patterns at the 10 dB beam width pointas shown in Figure 1 The beam tracking can be expressedas

Beam tracking = max (1003816100381610038161003816119871minus119871minus 119871+119871

10038161003816100381610038161003816100381610038161003816119871minus119877minus 119871+119877

1003816100381610038161003816) (1)

where 119871minus119871

is the level of minus45∘ polarization at the 10 dB pointon the left 119871

+119871is the level of +45∘ polarization at the 10 dB

point on the left 119871minus119877

is the level of minus45∘ polarization atthe 10 dB point on the right and 119871

+119877is the level of +45∘

polarization at the 10 dB point on the right The smaller thebeam tracking is the better the symmetry of the radiation

pattern is Ideally the value of beam tracking is expected tobe 0 which means that the two patterns coincide completelyat the 10 dB point In [11] the authors supposed that theboresight was the axis of symmetry of the antenna Howeverfor most antennas the boresight is not the symmetry axisof the antenna because the beam is always tilted to oneside more or less In this case only the amplitude is notenough to describe the radiation pattern symmetry but alsothe angular dimension the beam squint The beam squint isdefined as the ratio of the boresight angle to the 10 dB beamwidth

Beam squint =boresight angle10 dB beam width

(2)

Ideally the value of beam squint is expected to be 0 whichmeans that the boresight is just the symmetry axis of theantenna The beam tracking and the beam squint describethe symmetric property of the dual-polarized antenna in theamplitude domain and the angular domain respectively

In this paper a novel compact 1 times 10 dual slant-polarizedantenna array with excellent pattern symmetry propertyis presented The proposed antenna array operates in thefrequency band from 1710 to 2690MHz with a size of 105times 1300 times 37mm The fractional bandwidth of the antennaarray is 445 which could be classified as ultra wideband(UWB) antenna according to the definition of UWB antennaby the Federal Communications Commission (FCC) andthe International Telecommunication Union Radio (ITU-R)[12] The simulations of the proposed antenna are performedusing the commercial electromagnetic simulation softwareHFSS In the whole range of 10 dB beam width the worstbeam tracking of the array element is 040 dB which hasbeen improved about 24 compared with the result as05398 dB in [11] And the beam squint values are betterthan 1 The antenna array also provides excellent patternsymmetry property A prototype of the proposed antennaarray was fabricated and measured in an anechoic chamberThe experimental measurements concerning the antennaparameters are found to be in good agreement with thenumerical results

2 Antenna Array Structure and Design

21 Antenna Array Element The pattern symmetry propertyof the antenna array is mainly decided by the propertiesof the array element so the design of the array element isquite importantThe geometry of the proposed antenna arrayelement is shown in Figure 2 The dual slant-polarized arrayelement is composed of 2 evolved bow-tie antennas on a105mm wide reflector and the total height is 37mm Theevolutionary process from bow-tie antenna to the proposedarray element is shown in Figure 3 The bow-tie antenna isa kind of antenna with two flaring triangular shaped armswhich is a typical wide band antenna [13] By adding sloton the arms the equivalent electrical length of the arms isincreased so as tominiaturize the dimensions of the antennaThe array element has a strictly symmetrical structure whichis expected to obtain good radiation symmetry property Thefeeding structure of the array element is shown in Figure 4

International Journal of Antennas and Propagation 3

(a) (b) (c)

Figure 2 The geometry of the array element (a) 3D view (b) top view (c) and side view

(a) (b) (c) (d)

Figure 3The evolution from bow-tie antenna to the proposed array element (a) bow-tie antenna (b) bow-tie antenna with slots (c) bow-tieantenna with slots and holes and (d) the proposed array element

(a) (b) (c)

Figure 4 The feeding structure of the dipole (a) 3D view (b) the feeding structure for minus45∘ and (c) the feeding structure for +45∘

By adjusting the shape and the dimensions of the innerconductor the antenna can be matched to 50Ω transmissionlines in a bandwidth of 1710MHzndash2690MHz Besides thatthere are some holes in the arms and some raised blocks atthe edge of the arms which are brought in to tune the returnloss over the whole frequency band

22 Antenna Array Based on the array element above a uni-form linear antenna array is designedThe proposed antenna

array is composed of 10 elements and the spacing betweenthe elements was set to 110mm based on the frequencycharacteristic The structure of the antenna array is shown inFigure 5 The antenna array is fed by two 1 to 10 air dielectricstrip-line power splitters which are connected with the 10elements through several coaxial cables as shown in Figure 6The air dielectric strip-line has quite low transmission losswhich contributes to the gain of the antenna The amplitudeof each dipole could be conveniently adjusted by adjusting

4 International Journal of Antennas and Propagation

110

mm

1100mm

110mm

Figure 5 The structure of the antenna array

To dipole 3

To dipole 4To dipole 5 To dipole 6

To dipole 7

To dipole 8To dipole 9

To dipole 10

To antenna port

To dipole 1

To dipole 2

Figure 6 The feeding structure of the antenna array

Table 1 The simulated beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 004 005 005 0062200 006 006 007 0072690 008 009 009 010

the impedance of the corresponding matching section andthe phase of each dipole could be adjusted by adjusting thecorresponding cable length The dimensions of the antennaarray are 105 times 1100 times 37mm

3 Antenna ArraySimulation and Measurement

A commercial electromagnetic simulation software HFSS isused to analyze the performance of the proposed antennaelement and the antenna array The weight of the amplitudeand the phase of each element were optimized to achieve alow upper side lobe level which is quite critical for a wirelesstelecommunication system base station The antenna arrayhas around 65 degrees beam-width inH-plane which is quitesuitable for base station of mobile communicationThe beamtracking and the beam squint of the array element and theantenna array are calculated in E-plane and H-plane Thesimulated results of the beam tracking are shown in Table 1The simulated beam squint results of the array element andthe antenna array are shown in Tables 2 and 3 respectivelyThe simulated results show that both the proposed antennaelement and the antenna array have quite good patternsymmetry property

Table 2 The simulated beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 035 030 038 0342200 048 053 049 0572690 053 058 060 058

Table 3 The simulated beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 035 032 039 0342200 050 055 049 0582690 056 059 061 060

A prototype of the proposed antenna array was fab-ricated for measurement The array elements were madeof aluminum for its good processing property and coatedwith Tin to prevent the surface oxidation The picture ofthe proposed antenna array prototype is shown in Figure 7while the numerical andmeasurement results concerning thefrequency behavior of the 119878 parameters of the antenna arereported in Figure 8

The measurement of radiation patterns was carried outin an enclosed anechoic chamber The simulated and themeasured radiation patterns in H-plane and E-plane areshown in Figures 9 and 10 respectively

The simulated and the measured gain curves of theproposed antenna array are shown in Figure 11 However themeasured gain data of the antenna is approximately 01 dBbelow the predicted values in the operation frequency bandThe reason for this behavior is probably coupling withinthe cable loss andor the nonideal power distribution of thepower dividers

International Journal of Antennas and Propagation 5

(a) (b)

(c)

Figure 7The photo of the proposed antenna array (a) top view of the array element (b) side view of the array element and (c) the proposedantenna array

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)

1710 1850 1990 2130 2270 2410 2550 2690

S22 simulatedS11 measuredS11 simulated

S22 measured

S11

andS22

(a)

1710 1850 1990 2130 2270 2410 2550 2690

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)S21 simulatedS21 measured

S21

(b)

Figure 8 The simulated and measured 119878 parameters of the proposed antenna array (a) |11987811

| and |11987822

| and (b) |11987821

|

The beam tracking and the beam squint of the arrayelement and antenna array are measured in E-plane and H-plane the measured results of the beam tracking are shownin Table 4 The measured beam squint results of the arrayelement and the antenna array are shown in Tables 5 and6 respectively The measured array element beam trackingresults are better than 040 dB which is about 24 betterthan the results as 05398 dB in [11] And the measuredantenna array beam tracking results are better than 041 dBBesides that all the measured results of the beam squintare better than 1 The measured data agree very well with

the numerical results and show attractive pattern symmetrycharacteristics for a MIMO base station

4 Conclusion

In this paper a novel compact 1 times 10 dual slant-polarizedantenna array with excellent pattern symmetry propertyhas been proposed The antenna array is composed of10 dual slant-polarized antenna array elements whichevolved from the bow-tie antennas The antenna arrayoperates in the frequency band 1710ndash2690MHz with a size

6 International Journal of Antennas and Propagation

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz minus45∘

(a)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz +45∘

(b)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz minus45∘

(c)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz +45∘

(d)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz minus45∘

(e)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz +45∘

(f)

Figure 9 The simulated and measured radiation patterns in H-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

International Journal of Antennas and Propagation 7

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz minus45∘

(a)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz +45∘

(b)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz minus45∘

(c)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz +45∘

(d)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz minus45∘

(e)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz +45∘

(f)

Figure 10 The simulated and measured radiation patterns in E-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

8 International Journal of Antennas and Propagation

1710 1850 1990 2130 2270 2410 2550 2690

170

175

180

185

190

Gai

n

Simulatedminus45 measured+45 measured

Frequency (MHz)

Figure 11 The gain of the proposed antenna array

Table 4Themeasured beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 026 026 027 0282200 036 036 037 0372690 040 041 040 040

Table 5 The measured beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 080 074 058 0552200 065 063 070 0672690 052 047 056 053

Table 6 The measured beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 082 075 069 0542200 071 069 072 0732690 066 051 060 061

of 105 lowast 1300 lowast 37mm only Two parameters the beamtracking and the beam squint that quantitatively describethe pattern symmetry were presented The results show thatthe pattern symmetry property of the single antenna elementhas been improved about 24 compared with the formerstudy and the antenna array also provides excellent patternsymmetry property

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to express their sincere gratitudeto MOBI Antenna Technologies (Shenzhen) Company forproviding the software package of HFSS and antenna testchamber This work was supported in part by the KeyProgram of the National Natural Science Foundation ofChina underGrant 61032003 and theNational Basic ResearchProgram of China under Grant 2009CB320402

References

[1] J F Valenzuela-Valdes M A Garcıa-Fernandez A MMartınez-Gonzalez and D A Sanchez-Hernandez ldquoEvalua-tion of true polarization diversity for MIMO systemsrdquo IEEETransactions on Antennas and Propagation vol 57 no 9 pp2746ndash2755 2009

[2] P-S Kildal and K Rosengren ldquoCorrelation and capacity ofMIMO systems and mutual coupling radiation efficiency anddiversity gain of their antennas simulations and measurementsin a reverberation chamberrdquo IEEE Communications Magazinevol 42 no 12 pp 104ndash112 2004

[3] K S Min D J Kim and M S Kim ldquoMulti-channel MIMOantenna design forWiBroPCS bandrdquo in Proceedings of the IEEEInternational Symposium on Antennas and Propagation Societypp 1225ndash1228 Honolulu Hawaii USA July 2007

[4] M A Jensen and J W Wallace ldquoA review of antennas andpropagation for MIMOwireless communicationsrdquo IEEE Trans-actions on Antennas and Propagation vol 52 no 11 pp 2810ndash2824 2004

[5] J Lee and N Jindal ldquoSymmetrie capacity of MIMO downlinkchannelsrdquo in Proceedings of the IEEE International Symposiumon Information Theory (ISIT rsquo06) pp 1031ndash1035 Seattle WashUSA July 2006

[6] L Dong H Choo R W Heath Jr and H Ling ldquoSimulationofMIMO channel capacity with antenna polarization diversityrdquoIEEE Transactions onWireless Communications vol 4 no 4 pp1869ndash1873 2005

[7] J Perez J Ibanez L Vielva and I Santamarıa ldquoCapacity esti-mation of polarization-diversity MIMO systems in Urbanmicrocellular environmentsrdquo in Proceedings of the 15th IEEEInternational Symposium on Personal Indoor and Mobile RadioCommunications (PIMRC rsquo04) vol 4 pp 2730ndash2734 September2004

[8] R Chair A A Kishk and K F Lee ldquoComparative study ondifferent feeding techniques for dual polarized dielectric reso-nator antennasrdquo in IEEE Antennas and Propagation SocietyInternational Symposium pp 2495ndash2498 Albuquerque NMUSA 2006

[9] Y Gao Z Feng and L Zhang ldquoCompact CPW-fed dielectricresonator antenna with dual polarizationrdquo IEEE Antennas andWireless Propagation Letters vol 10 pp 544ndash547 2011

[10] A C K Mak and C Rowell ldquoA low-cost dual-polarized wide-band antennardquo in Proceedings of the IEEE International Sym-posium on Antennas and Propagation Society pp 1478ndash1479Orlando Fla USA July 2013

International Journal of Antennas and Propagation 9

[11] J S Kim J H Yoon Y J Yoon W-S Lee and C-G KimldquoDesign of modified dual mode horn antenna to improve EH-plane radiation pattern symmetryrdquo in Proceedings of the 17thInternational Symposium on Antennas and Propagation (ISAPrsquo12) pp 547ndash550 Nagoys Japan November 2012

[12] F Gross Frontiers in Antennas Next Generation Design ampEngineering McGraw-Hill New York NY USA 2011

[13] E A Soliman S Brebels P Delmotte G A E Vandenboschand E Beyne ldquoBow-tie slot antenna fed by CPWrdquo ElectronicsLetters vol 35 no 7 pp 514ndash515 1999

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of Antennas and Propagation 3

(a) (b) (c)

Figure 2 The geometry of the array element (a) 3D view (b) top view (c) and side view

(a) (b) (c) (d)

Figure 3The evolution from bow-tie antenna to the proposed array element (a) bow-tie antenna (b) bow-tie antenna with slots (c) bow-tieantenna with slots and holes and (d) the proposed array element

(a) (b) (c)

Figure 4 The feeding structure of the dipole (a) 3D view (b) the feeding structure for minus45∘ and (c) the feeding structure for +45∘

By adjusting the shape and the dimensions of the innerconductor the antenna can be matched to 50Ω transmissionlines in a bandwidth of 1710MHzndash2690MHz Besides thatthere are some holes in the arms and some raised blocks atthe edge of the arms which are brought in to tune the returnloss over the whole frequency band

22 Antenna Array Based on the array element above a uni-form linear antenna array is designedThe proposed antenna

array is composed of 10 elements and the spacing betweenthe elements was set to 110mm based on the frequencycharacteristic The structure of the antenna array is shown inFigure 5 The antenna array is fed by two 1 to 10 air dielectricstrip-line power splitters which are connected with the 10elements through several coaxial cables as shown in Figure 6The air dielectric strip-line has quite low transmission losswhich contributes to the gain of the antenna The amplitudeof each dipole could be conveniently adjusted by adjusting

4 International Journal of Antennas and Propagation

110

mm

1100mm

110mm

Figure 5 The structure of the antenna array

To dipole 3

To dipole 4To dipole 5 To dipole 6

To dipole 7

To dipole 8To dipole 9

To dipole 10

To antenna port

To dipole 1

To dipole 2

Figure 6 The feeding structure of the antenna array

Table 1 The simulated beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 004 005 005 0062200 006 006 007 0072690 008 009 009 010

the impedance of the corresponding matching section andthe phase of each dipole could be adjusted by adjusting thecorresponding cable length The dimensions of the antennaarray are 105 times 1100 times 37mm

3 Antenna ArraySimulation and Measurement

A commercial electromagnetic simulation software HFSS isused to analyze the performance of the proposed antennaelement and the antenna array The weight of the amplitudeand the phase of each element were optimized to achieve alow upper side lobe level which is quite critical for a wirelesstelecommunication system base station The antenna arrayhas around 65 degrees beam-width inH-plane which is quitesuitable for base station of mobile communicationThe beamtracking and the beam squint of the array element and theantenna array are calculated in E-plane and H-plane Thesimulated results of the beam tracking are shown in Table 1The simulated beam squint results of the array element andthe antenna array are shown in Tables 2 and 3 respectivelyThe simulated results show that both the proposed antennaelement and the antenna array have quite good patternsymmetry property

Table 2 The simulated beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 035 030 038 0342200 048 053 049 0572690 053 058 060 058

Table 3 The simulated beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 035 032 039 0342200 050 055 049 0582690 056 059 061 060

A prototype of the proposed antenna array was fab-ricated for measurement The array elements were madeof aluminum for its good processing property and coatedwith Tin to prevent the surface oxidation The picture ofthe proposed antenna array prototype is shown in Figure 7while the numerical andmeasurement results concerning thefrequency behavior of the 119878 parameters of the antenna arereported in Figure 8

The measurement of radiation patterns was carried outin an enclosed anechoic chamber The simulated and themeasured radiation patterns in H-plane and E-plane areshown in Figures 9 and 10 respectively

The simulated and the measured gain curves of theproposed antenna array are shown in Figure 11 However themeasured gain data of the antenna is approximately 01 dBbelow the predicted values in the operation frequency bandThe reason for this behavior is probably coupling withinthe cable loss andor the nonideal power distribution of thepower dividers

International Journal of Antennas and Propagation 5

(a) (b)

(c)

Figure 7The photo of the proposed antenna array (a) top view of the array element (b) side view of the array element and (c) the proposedantenna array

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)

1710 1850 1990 2130 2270 2410 2550 2690

S22 simulatedS11 measuredS11 simulated

S22 measured

S11

andS22

(a)

1710 1850 1990 2130 2270 2410 2550 2690

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)S21 simulatedS21 measured

S21

(b)

Figure 8 The simulated and measured 119878 parameters of the proposed antenna array (a) |11987811

| and |11987822

| and (b) |11987821

|

The beam tracking and the beam squint of the arrayelement and antenna array are measured in E-plane and H-plane the measured results of the beam tracking are shownin Table 4 The measured beam squint results of the arrayelement and the antenna array are shown in Tables 5 and6 respectively The measured array element beam trackingresults are better than 040 dB which is about 24 betterthan the results as 05398 dB in [11] And the measuredantenna array beam tracking results are better than 041 dBBesides that all the measured results of the beam squintare better than 1 The measured data agree very well with

the numerical results and show attractive pattern symmetrycharacteristics for a MIMO base station

4 Conclusion

In this paper a novel compact 1 times 10 dual slant-polarizedantenna array with excellent pattern symmetry propertyhas been proposed The antenna array is composed of10 dual slant-polarized antenna array elements whichevolved from the bow-tie antennas The antenna arrayoperates in the frequency band 1710ndash2690MHz with a size

6 International Journal of Antennas and Propagation

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz minus45∘

(a)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz +45∘

(b)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz minus45∘

(c)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz +45∘

(d)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz minus45∘

(e)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz +45∘

(f)

Figure 9 The simulated and measured radiation patterns in H-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

International Journal of Antennas and Propagation 7

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz minus45∘

(a)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz +45∘

(b)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz minus45∘

(c)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz +45∘

(d)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz minus45∘

(e)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz +45∘

(f)

Figure 10 The simulated and measured radiation patterns in E-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

8 International Journal of Antennas and Propagation

1710 1850 1990 2130 2270 2410 2550 2690

170

175

180

185

190

Gai

n

Simulatedminus45 measured+45 measured

Frequency (MHz)

Figure 11 The gain of the proposed antenna array

Table 4Themeasured beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 026 026 027 0282200 036 036 037 0372690 040 041 040 040

Table 5 The measured beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 080 074 058 0552200 065 063 070 0672690 052 047 056 053

Table 6 The measured beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 082 075 069 0542200 071 069 072 0732690 066 051 060 061

of 105 lowast 1300 lowast 37mm only Two parameters the beamtracking and the beam squint that quantitatively describethe pattern symmetry were presented The results show thatthe pattern symmetry property of the single antenna elementhas been improved about 24 compared with the formerstudy and the antenna array also provides excellent patternsymmetry property

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to express their sincere gratitudeto MOBI Antenna Technologies (Shenzhen) Company forproviding the software package of HFSS and antenna testchamber This work was supported in part by the KeyProgram of the National Natural Science Foundation ofChina underGrant 61032003 and theNational Basic ResearchProgram of China under Grant 2009CB320402

References

[1] J F Valenzuela-Valdes M A Garcıa-Fernandez A MMartınez-Gonzalez and D A Sanchez-Hernandez ldquoEvalua-tion of true polarization diversity for MIMO systemsrdquo IEEETransactions on Antennas and Propagation vol 57 no 9 pp2746ndash2755 2009

[2] P-S Kildal and K Rosengren ldquoCorrelation and capacity ofMIMO systems and mutual coupling radiation efficiency anddiversity gain of their antennas simulations and measurementsin a reverberation chamberrdquo IEEE Communications Magazinevol 42 no 12 pp 104ndash112 2004

[3] K S Min D J Kim and M S Kim ldquoMulti-channel MIMOantenna design forWiBroPCS bandrdquo in Proceedings of the IEEEInternational Symposium on Antennas and Propagation Societypp 1225ndash1228 Honolulu Hawaii USA July 2007

[4] M A Jensen and J W Wallace ldquoA review of antennas andpropagation for MIMOwireless communicationsrdquo IEEE Trans-actions on Antennas and Propagation vol 52 no 11 pp 2810ndash2824 2004

[5] J Lee and N Jindal ldquoSymmetrie capacity of MIMO downlinkchannelsrdquo in Proceedings of the IEEE International Symposiumon Information Theory (ISIT rsquo06) pp 1031ndash1035 Seattle WashUSA July 2006

[6] L Dong H Choo R W Heath Jr and H Ling ldquoSimulationofMIMO channel capacity with antenna polarization diversityrdquoIEEE Transactions onWireless Communications vol 4 no 4 pp1869ndash1873 2005

[7] J Perez J Ibanez L Vielva and I Santamarıa ldquoCapacity esti-mation of polarization-diversity MIMO systems in Urbanmicrocellular environmentsrdquo in Proceedings of the 15th IEEEInternational Symposium on Personal Indoor and Mobile RadioCommunications (PIMRC rsquo04) vol 4 pp 2730ndash2734 September2004

[8] R Chair A A Kishk and K F Lee ldquoComparative study ondifferent feeding techniques for dual polarized dielectric reso-nator antennasrdquo in IEEE Antennas and Propagation SocietyInternational Symposium pp 2495ndash2498 Albuquerque NMUSA 2006

[9] Y Gao Z Feng and L Zhang ldquoCompact CPW-fed dielectricresonator antenna with dual polarizationrdquo IEEE Antennas andWireless Propagation Letters vol 10 pp 544ndash547 2011

[10] A C K Mak and C Rowell ldquoA low-cost dual-polarized wide-band antennardquo in Proceedings of the IEEE International Sym-posium on Antennas and Propagation Society pp 1478ndash1479Orlando Fla USA July 2013

International Journal of Antennas and Propagation 9

[11] J S Kim J H Yoon Y J Yoon W-S Lee and C-G KimldquoDesign of modified dual mode horn antenna to improve EH-plane radiation pattern symmetryrdquo in Proceedings of the 17thInternational Symposium on Antennas and Propagation (ISAPrsquo12) pp 547ndash550 Nagoys Japan November 2012

[12] F Gross Frontiers in Antennas Next Generation Design ampEngineering McGraw-Hill New York NY USA 2011

[13] E A Soliman S Brebels P Delmotte G A E Vandenboschand E Beyne ldquoBow-tie slot antenna fed by CPWrdquo ElectronicsLetters vol 35 no 7 pp 514ndash515 1999

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

4 International Journal of Antennas and Propagation

110

mm

1100mm

110mm

Figure 5 The structure of the antenna array

To dipole 3

To dipole 4To dipole 5 To dipole 6

To dipole 7

To dipole 8To dipole 9

To dipole 10

To antenna port

To dipole 1

To dipole 2

Figure 6 The feeding structure of the antenna array

Table 1 The simulated beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 004 005 005 0062200 006 006 007 0072690 008 009 009 010

the impedance of the corresponding matching section andthe phase of each dipole could be adjusted by adjusting thecorresponding cable length The dimensions of the antennaarray are 105 times 1100 times 37mm

3 Antenna ArraySimulation and Measurement

A commercial electromagnetic simulation software HFSS isused to analyze the performance of the proposed antennaelement and the antenna array The weight of the amplitudeand the phase of each element were optimized to achieve alow upper side lobe level which is quite critical for a wirelesstelecommunication system base station The antenna arrayhas around 65 degrees beam-width inH-plane which is quitesuitable for base station of mobile communicationThe beamtracking and the beam squint of the array element and theantenna array are calculated in E-plane and H-plane Thesimulated results of the beam tracking are shown in Table 1The simulated beam squint results of the array element andthe antenna array are shown in Tables 2 and 3 respectivelyThe simulated results show that both the proposed antennaelement and the antenna array have quite good patternsymmetry property

Table 2 The simulated beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 035 030 038 0342200 048 053 049 0572690 053 058 060 058

Table 3 The simulated beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 035 032 039 0342200 050 055 049 0582690 056 059 061 060

A prototype of the proposed antenna array was fab-ricated for measurement The array elements were madeof aluminum for its good processing property and coatedwith Tin to prevent the surface oxidation The picture ofthe proposed antenna array prototype is shown in Figure 7while the numerical andmeasurement results concerning thefrequency behavior of the 119878 parameters of the antenna arereported in Figure 8

The measurement of radiation patterns was carried outin an enclosed anechoic chamber The simulated and themeasured radiation patterns in H-plane and E-plane areshown in Figures 9 and 10 respectively

The simulated and the measured gain curves of theproposed antenna array are shown in Figure 11 However themeasured gain data of the antenna is approximately 01 dBbelow the predicted values in the operation frequency bandThe reason for this behavior is probably coupling withinthe cable loss andor the nonideal power distribution of thepower dividers

International Journal of Antennas and Propagation 5

(a) (b)

(c)

Figure 7The photo of the proposed antenna array (a) top view of the array element (b) side view of the array element and (c) the proposedantenna array

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)

1710 1850 1990 2130 2270 2410 2550 2690

S22 simulatedS11 measuredS11 simulated

S22 measured

S11

andS22

(a)

1710 1850 1990 2130 2270 2410 2550 2690

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)S21 simulatedS21 measured

S21

(b)

Figure 8 The simulated and measured 119878 parameters of the proposed antenna array (a) |11987811

| and |11987822

| and (b) |11987821

|

The beam tracking and the beam squint of the arrayelement and antenna array are measured in E-plane and H-plane the measured results of the beam tracking are shownin Table 4 The measured beam squint results of the arrayelement and the antenna array are shown in Tables 5 and6 respectively The measured array element beam trackingresults are better than 040 dB which is about 24 betterthan the results as 05398 dB in [11] And the measuredantenna array beam tracking results are better than 041 dBBesides that all the measured results of the beam squintare better than 1 The measured data agree very well with

the numerical results and show attractive pattern symmetrycharacteristics for a MIMO base station

4 Conclusion

In this paper a novel compact 1 times 10 dual slant-polarizedantenna array with excellent pattern symmetry propertyhas been proposed The antenna array is composed of10 dual slant-polarized antenna array elements whichevolved from the bow-tie antennas The antenna arrayoperates in the frequency band 1710ndash2690MHz with a size

6 International Journal of Antennas and Propagation

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz minus45∘

(a)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz +45∘

(b)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz minus45∘

(c)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz +45∘

(d)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz minus45∘

(e)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz +45∘

(f)

Figure 9 The simulated and measured radiation patterns in H-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

International Journal of Antennas and Propagation 7

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz minus45∘

(a)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz +45∘

(b)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz minus45∘

(c)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz +45∘

(d)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz minus45∘

(e)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz +45∘

(f)

Figure 10 The simulated and measured radiation patterns in E-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

8 International Journal of Antennas and Propagation

1710 1850 1990 2130 2270 2410 2550 2690

170

175

180

185

190

Gai

n

Simulatedminus45 measured+45 measured

Frequency (MHz)

Figure 11 The gain of the proposed antenna array

Table 4Themeasured beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 026 026 027 0282200 036 036 037 0372690 040 041 040 040

Table 5 The measured beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 080 074 058 0552200 065 063 070 0672690 052 047 056 053

Table 6 The measured beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 082 075 069 0542200 071 069 072 0732690 066 051 060 061

of 105 lowast 1300 lowast 37mm only Two parameters the beamtracking and the beam squint that quantitatively describethe pattern symmetry were presented The results show thatthe pattern symmetry property of the single antenna elementhas been improved about 24 compared with the formerstudy and the antenna array also provides excellent patternsymmetry property

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to express their sincere gratitudeto MOBI Antenna Technologies (Shenzhen) Company forproviding the software package of HFSS and antenna testchamber This work was supported in part by the KeyProgram of the National Natural Science Foundation ofChina underGrant 61032003 and theNational Basic ResearchProgram of China under Grant 2009CB320402

References

[1] J F Valenzuela-Valdes M A Garcıa-Fernandez A MMartınez-Gonzalez and D A Sanchez-Hernandez ldquoEvalua-tion of true polarization diversity for MIMO systemsrdquo IEEETransactions on Antennas and Propagation vol 57 no 9 pp2746ndash2755 2009

[2] P-S Kildal and K Rosengren ldquoCorrelation and capacity ofMIMO systems and mutual coupling radiation efficiency anddiversity gain of their antennas simulations and measurementsin a reverberation chamberrdquo IEEE Communications Magazinevol 42 no 12 pp 104ndash112 2004

[3] K S Min D J Kim and M S Kim ldquoMulti-channel MIMOantenna design forWiBroPCS bandrdquo in Proceedings of the IEEEInternational Symposium on Antennas and Propagation Societypp 1225ndash1228 Honolulu Hawaii USA July 2007

[4] M A Jensen and J W Wallace ldquoA review of antennas andpropagation for MIMOwireless communicationsrdquo IEEE Trans-actions on Antennas and Propagation vol 52 no 11 pp 2810ndash2824 2004

[5] J Lee and N Jindal ldquoSymmetrie capacity of MIMO downlinkchannelsrdquo in Proceedings of the IEEE International Symposiumon Information Theory (ISIT rsquo06) pp 1031ndash1035 Seattle WashUSA July 2006

[6] L Dong H Choo R W Heath Jr and H Ling ldquoSimulationofMIMO channel capacity with antenna polarization diversityrdquoIEEE Transactions onWireless Communications vol 4 no 4 pp1869ndash1873 2005

[7] J Perez J Ibanez L Vielva and I Santamarıa ldquoCapacity esti-mation of polarization-diversity MIMO systems in Urbanmicrocellular environmentsrdquo in Proceedings of the 15th IEEEInternational Symposium on Personal Indoor and Mobile RadioCommunications (PIMRC rsquo04) vol 4 pp 2730ndash2734 September2004

[8] R Chair A A Kishk and K F Lee ldquoComparative study ondifferent feeding techniques for dual polarized dielectric reso-nator antennasrdquo in IEEE Antennas and Propagation SocietyInternational Symposium pp 2495ndash2498 Albuquerque NMUSA 2006

[9] Y Gao Z Feng and L Zhang ldquoCompact CPW-fed dielectricresonator antenna with dual polarizationrdquo IEEE Antennas andWireless Propagation Letters vol 10 pp 544ndash547 2011

[10] A C K Mak and C Rowell ldquoA low-cost dual-polarized wide-band antennardquo in Proceedings of the IEEE International Sym-posium on Antennas and Propagation Society pp 1478ndash1479Orlando Fla USA July 2013

International Journal of Antennas and Propagation 9

[11] J S Kim J H Yoon Y J Yoon W-S Lee and C-G KimldquoDesign of modified dual mode horn antenna to improve EH-plane radiation pattern symmetryrdquo in Proceedings of the 17thInternational Symposium on Antennas and Propagation (ISAPrsquo12) pp 547ndash550 Nagoys Japan November 2012

[12] F Gross Frontiers in Antennas Next Generation Design ampEngineering McGraw-Hill New York NY USA 2011

[13] E A Soliman S Brebels P Delmotte G A E Vandenboschand E Beyne ldquoBow-tie slot antenna fed by CPWrdquo ElectronicsLetters vol 35 no 7 pp 514ndash515 1999

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of Antennas and Propagation 5

(a) (b)

(c)

Figure 7The photo of the proposed antenna array (a) top view of the array element (b) side view of the array element and (c) the proposedantenna array

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)

1710 1850 1990 2130 2270 2410 2550 2690

S22 simulatedS11 measuredS11 simulated

S22 measured

S11

andS22

(a)

1710 1850 1990 2130 2270 2410 2550 2690

0

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Frequency (MHz)S21 simulatedS21 measured

S21

(b)

Figure 8 The simulated and measured 119878 parameters of the proposed antenna array (a) |11987811

| and |11987822

| and (b) |11987821

|

The beam tracking and the beam squint of the arrayelement and antenna array are measured in E-plane and H-plane the measured results of the beam tracking are shownin Table 4 The measured beam squint results of the arrayelement and the antenna array are shown in Tables 5 and6 respectively The measured array element beam trackingresults are better than 040 dB which is about 24 betterthan the results as 05398 dB in [11] And the measuredantenna array beam tracking results are better than 041 dBBesides that all the measured results of the beam squintare better than 1 The measured data agree very well with

the numerical results and show attractive pattern symmetrycharacteristics for a MIMO base station

4 Conclusion

In this paper a novel compact 1 times 10 dual slant-polarizedantenna array with excellent pattern symmetry propertyhas been proposed The antenna array is composed of10 dual slant-polarized antenna array elements whichevolved from the bow-tie antennas The antenna arrayoperates in the frequency band 1710ndash2690MHz with a size

6 International Journal of Antennas and Propagation

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz minus45∘

(a)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz +45∘

(b)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz minus45∘

(c)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz +45∘

(d)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz minus45∘

(e)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz +45∘

(f)

Figure 9 The simulated and measured radiation patterns in H-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

International Journal of Antennas and Propagation 7

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz minus45∘

(a)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz +45∘

(b)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz minus45∘

(c)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz +45∘

(d)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz minus45∘

(e)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz +45∘

(f)

Figure 10 The simulated and measured radiation patterns in E-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

8 International Journal of Antennas and Propagation

1710 1850 1990 2130 2270 2410 2550 2690

170

175

180

185

190

Gai

n

Simulatedminus45 measured+45 measured

Frequency (MHz)

Figure 11 The gain of the proposed antenna array

Table 4Themeasured beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 026 026 027 0282200 036 036 037 0372690 040 041 040 040

Table 5 The measured beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 080 074 058 0552200 065 063 070 0672690 052 047 056 053

Table 6 The measured beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 082 075 069 0542200 071 069 072 0732690 066 051 060 061

of 105 lowast 1300 lowast 37mm only Two parameters the beamtracking and the beam squint that quantitatively describethe pattern symmetry were presented The results show thatthe pattern symmetry property of the single antenna elementhas been improved about 24 compared with the formerstudy and the antenna array also provides excellent patternsymmetry property

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to express their sincere gratitudeto MOBI Antenna Technologies (Shenzhen) Company forproviding the software package of HFSS and antenna testchamber This work was supported in part by the KeyProgram of the National Natural Science Foundation ofChina underGrant 61032003 and theNational Basic ResearchProgram of China under Grant 2009CB320402

References

[1] J F Valenzuela-Valdes M A Garcıa-Fernandez A MMartınez-Gonzalez and D A Sanchez-Hernandez ldquoEvalua-tion of true polarization diversity for MIMO systemsrdquo IEEETransactions on Antennas and Propagation vol 57 no 9 pp2746ndash2755 2009

[2] P-S Kildal and K Rosengren ldquoCorrelation and capacity ofMIMO systems and mutual coupling radiation efficiency anddiversity gain of their antennas simulations and measurementsin a reverberation chamberrdquo IEEE Communications Magazinevol 42 no 12 pp 104ndash112 2004

[3] K S Min D J Kim and M S Kim ldquoMulti-channel MIMOantenna design forWiBroPCS bandrdquo in Proceedings of the IEEEInternational Symposium on Antennas and Propagation Societypp 1225ndash1228 Honolulu Hawaii USA July 2007

[4] M A Jensen and J W Wallace ldquoA review of antennas andpropagation for MIMOwireless communicationsrdquo IEEE Trans-actions on Antennas and Propagation vol 52 no 11 pp 2810ndash2824 2004

[5] J Lee and N Jindal ldquoSymmetrie capacity of MIMO downlinkchannelsrdquo in Proceedings of the IEEE International Symposiumon Information Theory (ISIT rsquo06) pp 1031ndash1035 Seattle WashUSA July 2006

[6] L Dong H Choo R W Heath Jr and H Ling ldquoSimulationofMIMO channel capacity with antenna polarization diversityrdquoIEEE Transactions onWireless Communications vol 4 no 4 pp1869ndash1873 2005

[7] J Perez J Ibanez L Vielva and I Santamarıa ldquoCapacity esti-mation of polarization-diversity MIMO systems in Urbanmicrocellular environmentsrdquo in Proceedings of the 15th IEEEInternational Symposium on Personal Indoor and Mobile RadioCommunications (PIMRC rsquo04) vol 4 pp 2730ndash2734 September2004

[8] R Chair A A Kishk and K F Lee ldquoComparative study ondifferent feeding techniques for dual polarized dielectric reso-nator antennasrdquo in IEEE Antennas and Propagation SocietyInternational Symposium pp 2495ndash2498 Albuquerque NMUSA 2006

[9] Y Gao Z Feng and L Zhang ldquoCompact CPW-fed dielectricresonator antenna with dual polarizationrdquo IEEE Antennas andWireless Propagation Letters vol 10 pp 544ndash547 2011

[10] A C K Mak and C Rowell ldquoA low-cost dual-polarized wide-band antennardquo in Proceedings of the IEEE International Sym-posium on Antennas and Propagation Society pp 1478ndash1479Orlando Fla USA July 2013

International Journal of Antennas and Propagation 9

[11] J S Kim J H Yoon Y J Yoon W-S Lee and C-G KimldquoDesign of modified dual mode horn antenna to improve EH-plane radiation pattern symmetryrdquo in Proceedings of the 17thInternational Symposium on Antennas and Propagation (ISAPrsquo12) pp 547ndash550 Nagoys Japan November 2012

[12] F Gross Frontiers in Antennas Next Generation Design ampEngineering McGraw-Hill New York NY USA 2011

[13] E A Soliman S Brebels P Delmotte G A E Vandenboschand E Beyne ldquoBow-tie slot antenna fed by CPWrdquo ElectronicsLetters vol 35 no 7 pp 514ndash515 1999

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

6 International Journal of Antennas and Propagation

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz minus45∘

(a)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

1710MHz +45∘

(b)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz minus45∘

(c)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2200MHz +45∘

(d)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz minus45∘

(e)

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0

Co-polar simulatedCo-polar measured

x-polar simulatedx-polar measured

0 60 120 180

2690MHz +45∘

(f)

Figure 9 The simulated and measured radiation patterns in H-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

International Journal of Antennas and Propagation 7

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz minus45∘

(a)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz +45∘

(b)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz minus45∘

(c)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz +45∘

(d)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz minus45∘

(e)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz +45∘

(f)

Figure 10 The simulated and measured radiation patterns in E-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

8 International Journal of Antennas and Propagation

1710 1850 1990 2130 2270 2410 2550 2690

170

175

180

185

190

Gai

n

Simulatedminus45 measured+45 measured

Frequency (MHz)

Figure 11 The gain of the proposed antenna array

Table 4Themeasured beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 026 026 027 0282200 036 036 037 0372690 040 041 040 040

Table 5 The measured beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 080 074 058 0552200 065 063 070 0672690 052 047 056 053

Table 6 The measured beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 082 075 069 0542200 071 069 072 0732690 066 051 060 061

of 105 lowast 1300 lowast 37mm only Two parameters the beamtracking and the beam squint that quantitatively describethe pattern symmetry were presented The results show thatthe pattern symmetry property of the single antenna elementhas been improved about 24 compared with the formerstudy and the antenna array also provides excellent patternsymmetry property

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to express their sincere gratitudeto MOBI Antenna Technologies (Shenzhen) Company forproviding the software package of HFSS and antenna testchamber This work was supported in part by the KeyProgram of the National Natural Science Foundation ofChina underGrant 61032003 and theNational Basic ResearchProgram of China under Grant 2009CB320402

References

[1] J F Valenzuela-Valdes M A Garcıa-Fernandez A MMartınez-Gonzalez and D A Sanchez-Hernandez ldquoEvalua-tion of true polarization diversity for MIMO systemsrdquo IEEETransactions on Antennas and Propagation vol 57 no 9 pp2746ndash2755 2009

[2] P-S Kildal and K Rosengren ldquoCorrelation and capacity ofMIMO systems and mutual coupling radiation efficiency anddiversity gain of their antennas simulations and measurementsin a reverberation chamberrdquo IEEE Communications Magazinevol 42 no 12 pp 104ndash112 2004

[3] K S Min D J Kim and M S Kim ldquoMulti-channel MIMOantenna design forWiBroPCS bandrdquo in Proceedings of the IEEEInternational Symposium on Antennas and Propagation Societypp 1225ndash1228 Honolulu Hawaii USA July 2007

[4] M A Jensen and J W Wallace ldquoA review of antennas andpropagation for MIMOwireless communicationsrdquo IEEE Trans-actions on Antennas and Propagation vol 52 no 11 pp 2810ndash2824 2004

[5] J Lee and N Jindal ldquoSymmetrie capacity of MIMO downlinkchannelsrdquo in Proceedings of the IEEE International Symposiumon Information Theory (ISIT rsquo06) pp 1031ndash1035 Seattle WashUSA July 2006

[6] L Dong H Choo R W Heath Jr and H Ling ldquoSimulationofMIMO channel capacity with antenna polarization diversityrdquoIEEE Transactions onWireless Communications vol 4 no 4 pp1869ndash1873 2005

[7] J Perez J Ibanez L Vielva and I Santamarıa ldquoCapacity esti-mation of polarization-diversity MIMO systems in Urbanmicrocellular environmentsrdquo in Proceedings of the 15th IEEEInternational Symposium on Personal Indoor and Mobile RadioCommunications (PIMRC rsquo04) vol 4 pp 2730ndash2734 September2004

[8] R Chair A A Kishk and K F Lee ldquoComparative study ondifferent feeding techniques for dual polarized dielectric reso-nator antennasrdquo in IEEE Antennas and Propagation SocietyInternational Symposium pp 2495ndash2498 Albuquerque NMUSA 2006

[9] Y Gao Z Feng and L Zhang ldquoCompact CPW-fed dielectricresonator antenna with dual polarizationrdquo IEEE Antennas andWireless Propagation Letters vol 10 pp 544ndash547 2011

[10] A C K Mak and C Rowell ldquoA low-cost dual-polarized wide-band antennardquo in Proceedings of the IEEE International Sym-posium on Antennas and Propagation Society pp 1478ndash1479Orlando Fla USA July 2013

International Journal of Antennas and Propagation 9

[11] J S Kim J H Yoon Y J Yoon W-S Lee and C-G KimldquoDesign of modified dual mode horn antenna to improve EH-plane radiation pattern symmetryrdquo in Proceedings of the 17thInternational Symposium on Antennas and Propagation (ISAPrsquo12) pp 547ndash550 Nagoys Japan November 2012

[12] F Gross Frontiers in Antennas Next Generation Design ampEngineering McGraw-Hill New York NY USA 2011

[13] E A Soliman S Brebels P Delmotte G A E Vandenboschand E Beyne ldquoBow-tie slot antenna fed by CPWrdquo ElectronicsLetters vol 35 no 7 pp 514ndash515 1999

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of Antennas and Propagation 7

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz minus45∘

(a)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

1710MHz +45∘

(b)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz minus45∘

(c)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2200MHz +45∘

(d)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz minus45∘

(e)

SimulatedMeasured

minus180

minus10

minus120

minus20

minus60

minus30

minus40

0 60 120 180

0

minus50

2690MHz +45∘

(f)

Figure 10 The simulated and measured radiation patterns in E-plane (a) 1710MHz minus45∘ (b) 1710MHz +45∘ (c) 2200MHz minus45∘(d) 22000MHz +45∘ (e) 2690MHz minus45∘ and (f) 2690MHz +45∘

8 International Journal of Antennas and Propagation

1710 1850 1990 2130 2270 2410 2550 2690

170

175

180

185

190

Gai

n

Simulatedminus45 measured+45 measured

Frequency (MHz)

Figure 11 The gain of the proposed antenna array

Table 4Themeasured beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 026 026 027 0282200 036 036 037 0372690 040 041 040 040

Table 5 The measured beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 080 074 058 0552200 065 063 070 0672690 052 047 056 053

Table 6 The measured beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 082 075 069 0542200 071 069 072 0732690 066 051 060 061

of 105 lowast 1300 lowast 37mm only Two parameters the beamtracking and the beam squint that quantitatively describethe pattern symmetry were presented The results show thatthe pattern symmetry property of the single antenna elementhas been improved about 24 compared with the formerstudy and the antenna array also provides excellent patternsymmetry property

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to express their sincere gratitudeto MOBI Antenna Technologies (Shenzhen) Company forproviding the software package of HFSS and antenna testchamber This work was supported in part by the KeyProgram of the National Natural Science Foundation ofChina underGrant 61032003 and theNational Basic ResearchProgram of China under Grant 2009CB320402

References

[1] J F Valenzuela-Valdes M A Garcıa-Fernandez A MMartınez-Gonzalez and D A Sanchez-Hernandez ldquoEvalua-tion of true polarization diversity for MIMO systemsrdquo IEEETransactions on Antennas and Propagation vol 57 no 9 pp2746ndash2755 2009

[2] P-S Kildal and K Rosengren ldquoCorrelation and capacity ofMIMO systems and mutual coupling radiation efficiency anddiversity gain of their antennas simulations and measurementsin a reverberation chamberrdquo IEEE Communications Magazinevol 42 no 12 pp 104ndash112 2004

[3] K S Min D J Kim and M S Kim ldquoMulti-channel MIMOantenna design forWiBroPCS bandrdquo in Proceedings of the IEEEInternational Symposium on Antennas and Propagation Societypp 1225ndash1228 Honolulu Hawaii USA July 2007

[4] M A Jensen and J W Wallace ldquoA review of antennas andpropagation for MIMOwireless communicationsrdquo IEEE Trans-actions on Antennas and Propagation vol 52 no 11 pp 2810ndash2824 2004

[5] J Lee and N Jindal ldquoSymmetrie capacity of MIMO downlinkchannelsrdquo in Proceedings of the IEEE International Symposiumon Information Theory (ISIT rsquo06) pp 1031ndash1035 Seattle WashUSA July 2006

[6] L Dong H Choo R W Heath Jr and H Ling ldquoSimulationofMIMO channel capacity with antenna polarization diversityrdquoIEEE Transactions onWireless Communications vol 4 no 4 pp1869ndash1873 2005

[7] J Perez J Ibanez L Vielva and I Santamarıa ldquoCapacity esti-mation of polarization-diversity MIMO systems in Urbanmicrocellular environmentsrdquo in Proceedings of the 15th IEEEInternational Symposium on Personal Indoor and Mobile RadioCommunications (PIMRC rsquo04) vol 4 pp 2730ndash2734 September2004

[8] R Chair A A Kishk and K F Lee ldquoComparative study ondifferent feeding techniques for dual polarized dielectric reso-nator antennasrdquo in IEEE Antennas and Propagation SocietyInternational Symposium pp 2495ndash2498 Albuquerque NMUSA 2006

[9] Y Gao Z Feng and L Zhang ldquoCompact CPW-fed dielectricresonator antenna with dual polarizationrdquo IEEE Antennas andWireless Propagation Letters vol 10 pp 544ndash547 2011

[10] A C K Mak and C Rowell ldquoA low-cost dual-polarized wide-band antennardquo in Proceedings of the IEEE International Sym-posium on Antennas and Propagation Society pp 1478ndash1479Orlando Fla USA July 2013

International Journal of Antennas and Propagation 9

[11] J S Kim J H Yoon Y J Yoon W-S Lee and C-G KimldquoDesign of modified dual mode horn antenna to improve EH-plane radiation pattern symmetryrdquo in Proceedings of the 17thInternational Symposium on Antennas and Propagation (ISAPrsquo12) pp 547ndash550 Nagoys Japan November 2012

[12] F Gross Frontiers in Antennas Next Generation Design ampEngineering McGraw-Hill New York NY USA 2011

[13] E A Soliman S Brebels P Delmotte G A E Vandenboschand E Beyne ldquoBow-tie slot antenna fed by CPWrdquo ElectronicsLetters vol 35 no 7 pp 514ndash515 1999

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

8 International Journal of Antennas and Propagation

1710 1850 1990 2130 2270 2410 2550 2690

170

175

180

185

190

Gai

n

Simulatedminus45 measured+45 measured

Frequency (MHz)

Figure 11 The gain of the proposed antenna array

Table 4Themeasured beam tracking computed in H-plane and E-plane

Freq(MHz)

H-plane E-planeElementbeam

tracking (dB)

Array beamtracking(dB)

Elementbeam

tracking (dB)

Array beamtracking(dB)

1710 026 026 027 0282200 036 036 037 0372690 040 041 040 040

Table 5 The measured beam squint of the array element

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 080 074 058 0552200 065 063 070 0672690 052 047 056 053

Table 6 The measured beam squint of the antenna array

Freq (MHz) H-plane E-planeminus45∘ +45∘ minus45∘ +45∘

1710 082 075 069 0542200 071 069 072 0732690 066 051 060 061

of 105 lowast 1300 lowast 37mm only Two parameters the beamtracking and the beam squint that quantitatively describethe pattern symmetry were presented The results show thatthe pattern symmetry property of the single antenna elementhas been improved about 24 compared with the formerstudy and the antenna array also provides excellent patternsymmetry property

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to express their sincere gratitudeto MOBI Antenna Technologies (Shenzhen) Company forproviding the software package of HFSS and antenna testchamber This work was supported in part by the KeyProgram of the National Natural Science Foundation ofChina underGrant 61032003 and theNational Basic ResearchProgram of China under Grant 2009CB320402

References

[1] J F Valenzuela-Valdes M A Garcıa-Fernandez A MMartınez-Gonzalez and D A Sanchez-Hernandez ldquoEvalua-tion of true polarization diversity for MIMO systemsrdquo IEEETransactions on Antennas and Propagation vol 57 no 9 pp2746ndash2755 2009

[2] P-S Kildal and K Rosengren ldquoCorrelation and capacity ofMIMO systems and mutual coupling radiation efficiency anddiversity gain of their antennas simulations and measurementsin a reverberation chamberrdquo IEEE Communications Magazinevol 42 no 12 pp 104ndash112 2004

[3] K S Min D J Kim and M S Kim ldquoMulti-channel MIMOantenna design forWiBroPCS bandrdquo in Proceedings of the IEEEInternational Symposium on Antennas and Propagation Societypp 1225ndash1228 Honolulu Hawaii USA July 2007

[4] M A Jensen and J W Wallace ldquoA review of antennas andpropagation for MIMOwireless communicationsrdquo IEEE Trans-actions on Antennas and Propagation vol 52 no 11 pp 2810ndash2824 2004

[5] J Lee and N Jindal ldquoSymmetrie capacity of MIMO downlinkchannelsrdquo in Proceedings of the IEEE International Symposiumon Information Theory (ISIT rsquo06) pp 1031ndash1035 Seattle WashUSA July 2006

[6] L Dong H Choo R W Heath Jr and H Ling ldquoSimulationofMIMO channel capacity with antenna polarization diversityrdquoIEEE Transactions onWireless Communications vol 4 no 4 pp1869ndash1873 2005

[7] J Perez J Ibanez L Vielva and I Santamarıa ldquoCapacity esti-mation of polarization-diversity MIMO systems in Urbanmicrocellular environmentsrdquo in Proceedings of the 15th IEEEInternational Symposium on Personal Indoor and Mobile RadioCommunications (PIMRC rsquo04) vol 4 pp 2730ndash2734 September2004

[8] R Chair A A Kishk and K F Lee ldquoComparative study ondifferent feeding techniques for dual polarized dielectric reso-nator antennasrdquo in IEEE Antennas and Propagation SocietyInternational Symposium pp 2495ndash2498 Albuquerque NMUSA 2006

[9] Y Gao Z Feng and L Zhang ldquoCompact CPW-fed dielectricresonator antenna with dual polarizationrdquo IEEE Antennas andWireless Propagation Letters vol 10 pp 544ndash547 2011

[10] A C K Mak and C Rowell ldquoA low-cost dual-polarized wide-band antennardquo in Proceedings of the IEEE International Sym-posium on Antennas and Propagation Society pp 1478ndash1479Orlando Fla USA July 2013

International Journal of Antennas and Propagation 9

[11] J S Kim J H Yoon Y J Yoon W-S Lee and C-G KimldquoDesign of modified dual mode horn antenna to improve EH-plane radiation pattern symmetryrdquo in Proceedings of the 17thInternational Symposium on Antennas and Propagation (ISAPrsquo12) pp 547ndash550 Nagoys Japan November 2012

[12] F Gross Frontiers in Antennas Next Generation Design ampEngineering McGraw-Hill New York NY USA 2011

[13] E A Soliman S Brebels P Delmotte G A E Vandenboschand E Beyne ldquoBow-tie slot antenna fed by CPWrdquo ElectronicsLetters vol 35 no 7 pp 514ndash515 1999

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of Antennas and Propagation 9

[11] J S Kim J H Yoon Y J Yoon W-S Lee and C-G KimldquoDesign of modified dual mode horn antenna to improve EH-plane radiation pattern symmetryrdquo in Proceedings of the 17thInternational Symposium on Antennas and Propagation (ISAPrsquo12) pp 547ndash550 Nagoys Japan November 2012

[12] F Gross Frontiers in Antennas Next Generation Design ampEngineering McGraw-Hill New York NY USA 2011

[13] E A Soliman S Brebels P Delmotte G A E Vandenboschand E Beyne ldquoBow-tie slot antenna fed by CPWrdquo ElectronicsLetters vol 35 no 7 pp 514ndash515 1999

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of