CMOS 60GHz Beamforming Circuit Design for Active Imaging Application

1
CMOS 60GHz Beamforming Circuit Design for Active
Imaging Application
Saihua Lin, Ada Poon, Simon Wong
saihua_at_stanford.edu, adapoon_at_stanford.edu,
wong_at_stanford.edu
Introduction
Design Overview
We plan to build a 60GHz beamforming
transceiver for active 3D imaging application.
By sending and receiving the signals
directionally, we can increase the spatial
resolution and reduce the interference. It is
also able to recover the depth information of a
target.

• We use TSMC 65nm GP process
• Pros VTH is low and noise performance is good
• Cons no RF MOSFET model and no MIM cap
• Alternative we can use MOM capacitor
• We need do RF MOSFET modeling

Difference for an inductor loaded amplifier

• Several techniques we will use
• Digital controlled complex phase shifting
• Sub antenna array configuration
• 3D image reconstruction by using wide band signal

Rx/Tx architecture

• There are 4 configurations for Tx and Rx.
  Configuration A is not good and now we use B.
  Finally we may use D.
• 2X2 beamforming receiver includes 4 LNAs and 4
  variable gain phase shifters. They are
  implemented by microstrip lines and CPW lines
• The same concept can be applied to transmitter.
  We use CPW lines and parallel combining
  techniques to design PA

Antenna Design

• Use scripts to generate one antenna and antenna
  arrays
• For 2X2 beamforming cirucit antennas, Rogers
  materials will be used as substrate
• Simulated gain is about 6.9dBi on RO4003, 8mil
  board

Chip Layout Simulation

• TSMC 65nm GP process
• LNA alone 7.2mA, 1V, NF4.2dB, S2117dB, S11
  and S22lt-15dB
• LNA variable gain phase shifter 32mA, 1V,
  NF4.3dB, S2129dB, S11 and S22lt-15dB
• 4 Channel circuit 131mA, 1V, S2137dB
• sub-PA VDD1V, PDC66mW, Max PAE22.9,
  Psat12.58dBm
• PA VDD1V, PDC128mW, Max PAE22.1,
  Psat15.4dBm, Gain19dB
• Tape out in 2010 January
• MSL, CPW, MOM, MOSFET Test structures
• sub-PA, 2 versions of LNAs, 2 versions of 1
  channel 4 channel circuit

Image Reconstruction
where s(x,y,?) is the response at the
transceiver, and
Where f(x,y,z) is the reflectivity function
2D FFT
3D FFT
Ref Three-Dimensional Millimeter-Wave imaging
for concealed weapon detection, TMTT 2001