A Current-Switching Phase Shifter for Millimeter-Wave Applications Chien M. TA, Efstratios SKAFIDAS, and Robin J. EVANS National ICT Australia (NICTA) Department of Electrical and Electronic Engineering The University of Melbourne

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A Current-Switching Phase Shifter
forMillimeter-Wave ApplicationsChien M. TA,
Efstratios SKAFIDAS, and Robin J. EVANSNational
ICT Australia (NICTA)Department of Electrical
and Electronic Engineering The University of
Melbourne
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Outline

• Introduction to 60-GHz wireless communications
• Phased-array antennae
• Phase shifter design
• Results
• Conclusions

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60 GHz wireless communications

• Unlicensed band
• 7GHz of bandwidth
• Multi-Gbps wireless communications
• High path loss
• 88dB free-space loss at 60GHz and 10m distance
• Additional attenuation due to oxygen absorption
• Phased-array antenna system
• Low cost
• CMOS technology

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Steerable antenna system

• Transmitter
• focus output power

Receiver improve SNR, reject interferers
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Array factor
Beam ß1 ß2 ß3 ?4
1 0 180 0 180
2 0 270 90 0
3 0 270 180 90
4 0 270 270 180
5 0 0 0 0
6 0 90 90 180
7 0 90 180 270
8 0 90 270 0
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Published 60-GHz phase shifters

• Alalusi CICC 2006
• Vector modulator
• Pros 360 phase control
• Cons high power consumption (72mW)
• Wu EuMIC 2007
• Vector modulator
• Pros continuous, 360 phase control
• Cons lossy (more than 17dB)
• Ta CCECE 2008
• Distributed
• Pros negligible power consumption
• Cons lossy, narrow phase control range

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Proposed phase shifter architecture

• Discrete phases determined by length of
  transmission line
• Current switching mode

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Schematic

• M0 input transconductance, sized and biased for
  high gain and low noise
• M1-4 switches
• V000, V090, V180, V270 digital input for phase
  control

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Layout

• 65-nm RF-CMOS
• Microstrip lines
• MIM capacitors
• 525µm 470µm

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Simulation results
90
90
90
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Simulation results (contd)
Frequency band 57 GHz to 66 GHz
Power supply 1.5 V
Power consumption 9 mW
Output phase 0, 90, 180, 270
Power loss lt 3 dB
Input return loss lt -6 .7 dB
Output return loss lt -10 dB
Noise figure 4.3 to 6.1 dB
IIP3 1.2 dBm
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Conclusions and future works

• Active phase shifter on CMOS
• 57 to 66 GHz
• 90-step output phase
• Low noise
• Digitally controlled
• Experimental works
• Chip is under fabrication
• Phase shifter measurement
• Antenna array measurement

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A Current-Switching Phase Shifter
forMillimeter-Wave ApplicationsTA, Chien M.,
SKAFIDAS, Efstratios, and EVANS, Robin J.
National ICT Australia (NICTA) Department of
Electrical and Electronic Engineering The
University of Melbourne