measurement of integrated pa-to-lna isolation on si cmos chip ryo minami , jeeyoung hong ,...
TRANSCRIPT
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
2010/12/10
R. Minami , Tokyo tech.
Measurement of Integrated PA-to-LNA Isolation on Si CMOS Chip
Ryo Minami , JeeYoung Hong ,Kenichi Okada , and Akira Matsuzawa
Tokyo Institute of Technology, Japan
2010/12/10
R. Minami , Tokyo tech.
2
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Outline
• Tx leakage and problem
• Evaluation of Tx leakage– Tx leakage paths
– Measurement and Simulation method
• Result
• Conclusion
2010/12/10
R. Minami , Tokyo tech.
3
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Background
• Merit– High frequency characteristic– High supply voltage
• Demerit– Chip area and cost
CMOS transistors can provide a sufficient performance for PA design.
The level of Tx leakage increases.
To investigate Tx leakage paths.
Conventionally, Power Amplifier (PA) has been implemented by compound semiconductors.
CMOS technology has been developed.
2010/12/10
R. Minami , Tokyo tech.
4
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Tx leakage and problem
FDD system
• The large transmitted signal leaks to Rx input side.• Tx leakage causes IM and degrades demodulation quality.
Tx leakage
interference signal
Rx signal
cross modulation
intermodulation distortion
Tx leakage
interference signal
Rx signal
LNA nonlinearity
Duplexer
PA
transmitted signal
received signal
LNATx
leakage
2010/12/10
R. Minami , Tokyo tech.
5
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Tx leakage paths
substrate couplinginductor couplingwire coupling (Vdd, GND)
conventional single-chip
The integration of the PA with other blocks increases many coupling paths.
Duplexer
LNA
PA
Duplexer
LNA
PA
2010/12/10
R. Minami , Tokyo tech.
6
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
p+ n+n+ p+ n+n+
- +gnd VDD
PA LNA
- +
p+ n+n+
gnd VDD
Air gap
Magnetic
p+ n+n+ p+ n+n+
- +gnd VDD
MagneticPA LNA
- +
p+ n+n+
gnd VDD
Substrate coupling
Dicing
Substrate coupling and inductor coupling are generated because PA and LNA are integrated on the same chip.
Substrate coupling is blocked by physically separating the PA and LNA[1].
[1] J.Y. Hong et al., IEICE society Conference, 2009.
2010/12/10
R. Minami , Tokyo tech.
7
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Measurement method
• substrate coupling
• inductor coupling• inductor coupling
After dicing, the distance between PA and LNA is 0.74mm, 1.55mm, 2.37mm, 3.20mm.
afterbeforesubstrate dicingdicingcoupling
GainGainSisolation
)(]dB[ LNAPA21
Chip
probe probe
absorber
Network Analyzer
PA LNA1 LNA2 LNA3 LNA4
-5dBm
Chip
absorber
probe
air gap
PA
probe
Network Analyzer
LNA1 LNA2 LNA3 LNA4
-5dBm
PA LNA
input output
isolation
S21
GLNAGPA
On-Chip
2010/12/10
R. Minami , Tokyo tech.
8
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Specification of the designed PA and LNA
PA
LNA
PA LNA
Technology 0.18 m CMOS process
Frequency 5 GHz
VDD 3.3 V 1.8 V
Gain at 5 GHz 5.5 dB 15.1 dB
NF at 5 GHz 2.7 dB
Area 1.01mm×1.01mm 0.70mm×1.01mm
2010/12/10
R. Minami , Tokyo tech.
9
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Simulation method
Magnetic coupling simulation by HFSS (an electromagnetic field simulator)
Circuit simulation with magnetic coupling effect by goldengate
The magnetic coupling between the inductor at PA output side and the inductor at LNA input side is the most dominant.
Assume
On-chip50 W
input
output
3.3 V
1.8 V
Magnetic coupling
PA LNA
PAinductor
LNAinductor
distance
104m
(1.5 turn)
(2.5 turn)
160m0.74mm1.55mm2.37mm3.20mm
2010/12/10
R. Minami , Tokyo tech.
10
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Simulation result
• Gain of PA and LNA are shown at 5 GHz
• S21 depends on the distance between PA and LNA
-160
-140
-120
-100
-80
-60
-40
0 1 2 3 4 5 6 7 8 9 10
Frequency[GHz]
S2
1[d
B]
0.74mm 1.55mm2.37mm 3.2mm
Gain of PA and LNA
2010/12/10
R. Minami , Tokyo tech.
11
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
-160
-140
-120
-100
-80
-60
-40
0 1 2 3 4 5 6 7 8 9 10frequency[GHz]
S2
1 [d
B]
0.74mm 1.55mm
2.37mm 3.2mm
sim.: dotted
meas.: solid
-160
-140
-120
-100
-80
-60
-40
0 1 2 3 4 5 6 7 8 9 10frequency[GHz]
S2
1 [d
B]
0.74mm 1.55mm
2.37mm 3.2mm
sim.: dotted
meas.: solid
noise flooror
thermal noise
probe coupling
• Under 3 GHz– Thermal noise from the resistance of LNA– Noise floor of the network analyzer
• Around 5 GHz– Noise floor of the network analyzer with gain
• Over 8 GHz– Probe coupling exists.
Assume
Measurement result
2010/12/10
R. Minami , Tokyo tech.
12
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Noise floor and probe coupling
● Noise floor ● Probe coupling
Network Analyzer
open(=S21)
3cm
probe probe
2cm
absorber
-5dBm
S21 with 3 cm distance between probes and 2cm distance between probe and absorber
Noise floorS21 with 4 patterns of probe distance and 0.3mm distance between probe and absorber
Probe coupling
Network Analyzer
coupling(=S21)
0.98mm,1.8mm,2.62mm,3.45mm
0.3mm
absorber
-5dBm
probe probe
2010/12/10
R. Minami , Tokyo tech.
13
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Probe coupling problem● The case of measuring chip
● The case of measuring probe coupling
Signal flows into the chip.
This is the worst case of probe coupling.
Chip
probe probe
PA LNA
couplingsignal
signal
absorberGND
probe probe
absorber
couplingsignal
0.3mm
2010/12/10
R. Minami , Tokyo tech.
14
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Thermal noise from the resistance of LNA
outcableLNALNAthermal NALossGainNFTBNoise )k(Log10]dB[
: noise calculation pointNetwork Analyzer
PA LNAinput output
×(a)
GLNAGPA
On-Chip
-5dBm
k: 1.38*10-23 [J/K]T: 300 [K]
B: 10 [Hz]Cable loss:2 [dB]
2010/12/10
R. Minami , Tokyo tech.
15
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Result of error analysis (higher and lower side)
-160
-140
-120
-100
-80
-60
-40
0 1 2 3 4 5 6 7 8 9 10frequency[GHz]
S2
1&
Th
erm
al
no
ise
[d
B]
0.74mmprobe coupingnoise floornoise
NAthermal
• Under 3 GHz– Noise floor of the network analyzer
• Over 8 GHz– Probe coupling exists.
2010/12/10
R. Minami , Tokyo tech.
16
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
• Around 5 GHz– Noise floor of network analyzer with gain
Result of error analysis (middle section)
dB80)GHz5( LNAPA GainGainnoisefloor
-160
-140
-120
-100
-80
-60
-40
0 1 2 3 4 5 6 7 8 9 10frequency[GHz]
S2
1 [
dB
]
0.74mm1.55mm2.37mm3.2mmnoise floor
GPA+GLNA
sim.: dottedmeas.: solid
2010/12/10
R. Minami , Tokyo tech.
17
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Comparison of coupling data at 5 GHz
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-110
-100
-90
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-60
-50
-40
0 1 2 3 4distance[mm]
Iso
lati
on
[d
B]
inductor coupling
simulation
noise floor
-120
-110
-100
-90
-80
-70
-60
-50
-40
0 1 2 3 4
distance[mm]
Iso
lati
on
[d
B]
all Tx leakage
inductor coupling
substrate coupling
Duplexer isolation
• The isolation value of inductor coupling is affected by the noise floor of the NA over 1.8mm distance between PA and LNA.
• Total isolation value becomes smaller than that of the duplexer over 0.4mm
• Substrate coupling is the most dominant factor in Tx leakage.
2010/12/10
R. Minami , Tokyo tech.
18
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Conclusion
• Substrate coupling is the most dominant factor in Tx leakage for Si substrate.
• Total isolation value becomes smaller than that of the duplexer over 0.4mm distance between PA and LNA.
• Error sources in measurement are noise floor of the network analyzer and probe coupling.
2010/12/10
R. Minami , Tokyo tech.
19
Matsuzawa& Okada Lab.
Matsuzawa Lab.Tokyo Institute of TechnologyMatsuzawa
& Okada Lab.Matsuzawa Lab.Tokyo Institute of Technology
Thank you for your attention!