development of a direct conversion multiband/multimode transmitter for wireless applications morgan...

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Development of a Direct Conversion Multiband/Multimode Transmitter for Wireless Applications Morgan Chen [email protected] Summer Undergraduate Research Experience (SURE) 2002 1 Department of Electrical Engineering and Computer Science University of California, Berkeley Berkeley, CA 94720 1 Department of Electrical and Computer Engineering Clemson University Clemson, SC 29634

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Development of a Direct Conversion Multiband/Multimode Transmitter for Wireless

Applications

Morgan Chen

[email protected]

Summer Undergraduate Research Experience (SURE) 20021

Department of Electrical Engineering and Computer Science

University of California, Berkeley

Berkeley, CA 94720

1Department of Electrical and Computer Engineering

Clemson University

Clemson, SC 29634

CLEMSONU N I V E R S I T

Y

• Motivation/Objectives

• Development and Design

• Fabrication of Transmitter

• Experimental Results

• Conclusion

Outline

CLEMSONU N I V E R S I T

Y

Motivation/Objectives

• Direct Conversion, or homodyne, has fewer components

• Fewer Components = Cheaper

• Multiband transmitters allow accessing multiple frequencies

• Ultimate goal of single chip design

Table of SpecificationsParameter Specified ValueBaseband frequencies 10-30 kHzBaseband input power <-3 dBmRF frequencies 1.9 GHz and 5.8 GHzRF power output 30 dBm for 1.9 GHz and 25 dBm for 5.8 GHz

CLEMSONU N I V E R S I T

Y

Development and Design

• Block Diagram

• CircuitCAM

CLEMSONU N I V E R S I T

Y

Block Diagram

LO = 1.9 GHz/5.8 GHz

Baseband Signal =10 - 30 kHz

BPF1: Assume3 dB

19.7 dBm (Max for the PAbefore the 1dB gain

compression pt. for 1.9 GHz)

SKY-7G

BPF2: Assume3 dB

MGA-83563

Switchingnetwork:

Assume 3 dBloss

PA3

MGA-83563

MGA-83563MGA-83563

15 dBm (Max for thePA before the 1dB

gain compression pt.for the 5.8 GHz)

PA4

PA3 PA3

CLEMSONU N I V E R S I T

Y

Design in CircuitCAM

Example layout of 5.8 GHz patch antenna

Example layout of switch

CLEMSONU N I V E R S I T

Y

Fabrication of Transmitter

CLEMSONU N I V E R S I T

Y

Mixer Close-up

CLEMSONU N I V E R S I T

Y

Switch Close-up

CLEMSONU N I V E R S I T

Y

Power Amplifier Close-up

CLEMSONU N I V E R S I T

Y

Antenna Close-up

CLEMSONU N I V E R S I T

Y

Experimental Results

Spectral plot of the SKY-7G mixer with IF = 100 KHz, LO = 1.9 GHz

CLEMSONU N I V E R S I T

Y

0.2 0.4 0.6 0.8 1 1.5 2 3 4 5 10 20 50

0.2

0.4

0.6

0.8 1

1.5

2

3

4

5

10

2050

-0.2

-0.4

-0.6

-0.8 -1

-1.5

-2

-3

-4

-5

-10

-20-50

3.8 GHz

7.8 GHz

S22HP 8719

07-15-2002 11:55:55

Smith Diagram for 5.8 GHz Patch Antenna

CLEMSONU N I V E R S I T

Y

-15

-10

-5

0

4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5

S22 MagnitudeHP 8719

07-15-2002 11:55:55

[dB

]

[GHz]

Standing Wave Ratio (SWR) Plot

CLEMSONU N I V E R S I T

Y

Just Curious

Transmitter with mixer and antenna alone at 5 feet

CLEMSONU N I V E R S I T

Y

Conclusions

• Direct conversion multiband/multimode transmitter technology is promising

• Design may require state of the art power amplifiers

• Switch is inefficient

• Switch also suffers from parasitics

• Future research means developing the PA and switch

• Future research also requires spectral masking

CLEMSONU N I V E R S I T

Y

Acknowledgements

•National Science Foundation

•Minicircuits’s Gerry Edson

•Agilent Technologies’ Creg Ballou

•NEC's California Eastern Laboratories' David Melton and Pam Cowan

•SURE advisor Dr. A. Pham

•Graduate students S. Thumaty, D. Newlin, C. Tompkins, X. Wang, S. Manohar, J. Rudbeck, M. Lockhard, R. Hanks, S. Chopra, and A. Keerti

•And last, but not least, Dr. D. Noneaker, Director of the SURE program at Clemson University

CLEMSONU N I V E R S I T

Y

Additional Slides

• Power Budget

• Transistor diagram of the switching network

• ADS

• Baseband Harmonic Problem

CLEMSONU N I V E R S I T

Y

Part Number Power out (dBm) Gain (dB) IP3 (dBm)Input Baseband at 1.9 GHz -3Input Baseband at 5.8 GHz -3Mixer = SKY-7G at 1.9 GHz -13 -10 10Mixer = SKY-7G at 5.8 GHz -13 -10 10Switching network for 1.9 GHz -16 -3Switching network for 5.8 GHz -16 -3BPF1 = Make ourselves -19 -3BPF2 = Make ourselves -19 -3PA1 = MGA-83563 0.35 19.35 29PA2 = MGA-83563 19.7 19.35 29PA3 = MGA-83563 -2 17 29PA4 = MGA-83563 15 17 29

Antenna: 1.9 GHz: Aceteq

Power Budget

CLEMSONU N I V E R S I T

Y

Transistor diagram of the switching network

VCC

VCC

Inverter

Delay

Pass GatesControl Line

Data Line

Line Out 1

Line Out 2

(CL=1)

(CL = 0)

SPDT

CLEMSONU N I V E R S I T

Y

Design in Advanced Design System

ADS Linecalc Tool

Transmitter Block Diagram

CLEMSONU N I V E R S I T

Y

Baseband Harmonic Images Problem

Wbaseband

abaseband

Wlo

alo

w

w

w

0.5*abaseband*alo

Wlo+WbasebandWlo-Wbaseband

Wlo

Small baseband frequencies = Spurious signals close to transmit signal!

CLEMSONU N I V E R S I T

Y

Thank You Very Much!