University of Toronto
(TH2B - 01)
65-GHz Doppler Sensor with On-Chip Antenna in 0.18µm SiGe BiCMOS
Terry Yao, Lamia Tchoketch-Kebir, Olga Yuryevich,
Michael Gordon and Sorin P. Voinigescu
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 2
Outline
• Motivation• System Overview and Design• Experimental Results• Conclusions• Acknowledgments
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 3
Motivation
• mm-wave integration in silicon accelerated by:Significantly smaller form factors of on-chip
passives (inductors, transformers, antennae)Advances in SiGe BiCMOS
• Target applications:mm-wave sensors
for medical and security applications
Short range automotive radar
Side Crash
Side Crash
Parking AidLane ChangeRear Crash(0.2-5m)
Parking Aid (0.2-5m)Stop-and-Go Traffic Radar (20m)Forward-Looking Radar(150m)
Blindsp
ot
BlindspotInte
rsec
tion
Intersection
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 4
State-of-the-Art in mm-Wave Integration
• SiGe favoured over CMOS due to higher breakdown voltage higher PA power, lower phase noise VCOs
• Critical challenge tuning BW, phase noise and output power of VCO
• No Tx/Rx IC with antenna and fundamental VCO
SystemAntenna on chip?
Integrated Fund. VCO?
Freq. (GHz)
Process (fT/fMAX) Reference
Tx
Y N 77 SiGe (200/250GHz) A. Natarajan (ISSCC, 2006)
Y N 60 SiGe (120/130GHz) C.H. Wang (ISSCC, 2006)
N N 60 SiGe (200/250GHz) B. Floyd (ISSCC, 2006)
Rx
Y N 77 SiGe (200/250GHz) A. Babakhani (ISSCC, 2006)
N Y 65 SiGe (150/160GHz) M. Gordon (SiRF, 2006)
N N 60 SiGe (200/250GHz) B. Floyd (ISSCC, 2006)
N N 60 0.13µm CMOS B. Razavi (ISSCC, 2005)
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 5
Integrated Fundamental Frequency VCO• Challenges:
Accurate fosc modeling of passives and parasitics Low phase noise high-Q tank, large BVCEO, large Vosc
High POUT large BVCEO, IBIAS, accurate matching Wide tuning range high capacitance-ratio varactors
• Benefits: Less EMI, no filtering required Area and power savings (multiplier structure, off-chip
transition eliminated, etc.) Higher integration level = lower overall cost
Note: Static frequency dividers equally important as VCO; so far only SiGe ones demonstrated >60GHz with low power
(T. Dickson, SiRF ’06; E. Laskin, BCTM ’06)
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 6
Outline
• Motivation• System Overview and Design• Experimental Results• Conclusions• Acknowledgments
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 7
System Highlights and Overview
• Extensive use of small footprint inductors as matching elements area savings
• HBT cascodes for higher gain, isolation
IF Amp
Output Buffer
IF
IF
Out
Out
On-Chip Patch Antenna
61-67GHz LO
LNA
Gilbert Mixer
Vdd Rx
Tx
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 8
System Design – Receive Path
2-stage single-ended
cascode LNA with vertically
stacked transformer output
Down-convert mixer noise- and
power-matched to 200Ω differential
Zout of LNA
RF+
RF-
IF+
IF-
EF
3.3V
Downconvert Mixer
3.3V
Vb6
IF Out+
IF Amplifier
IF Out-
Vb1
3.3V
RF In
Vb2
Vb3 Vb4
Patch Antenna
EF
LO+LO-
EF
LNA
Microstrip Feedline
Vb5
61-67GHz LO
To Tx
Bipolar IF amplifier
for reduced 1/f noise
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 9
System Design – Transmit Path
Differential Colpitts 61-
67GHz VCO (shared with
receive path)
2-Stage
emitter
follower
buffers
65GHz output buffer
driving 50Ω loads per
side
LO+MIXER
4V
Vtune
C1
C2 C2
LB
LE
LEE L
EE
LE
C1
Vdd
Vbb
4V
Out-LO+ LO-
EF
LO+
LO-
EF
To Rx Mixer
Output Buffer
Out+
On-Chip VCO
LB
LO-MIXER
LO+TX
LO-TX
Vb7
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 10
Building Blocks: Mixer
• Key design goals:
59-65GHz operation
Low noise at low IF
High conversion gain
• HBT for reduced 1/f noise
• Simultaneously noise- and power-matched to 200Ω differential LNA output
• Simulated: G ~ 9.2dB; IIP3 ~ 4.2dBm; NF ~ 13dB
• 13.2mW from 3.3V supplyinC
minffm ZR
gZj
gG
T
2
)(1
2
},min{ 3,3max, SATCECECco VVRIV
3,3 SATCECECC VVRI
3.3V
RF+
RF-
LO+
LO-
IF+
IF-
EF
Downconvert Mixer
RC
LE
LE
RC
LB
LB
Q1
Q2
Q3
Q4
Q5
Q6
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 11
mm-Wave Passives• Reduced form factor of on-chip passives at mm-waves
• Inductors preferred for area efficiency and low-loss
• ASITIC with >90% accuracy; 2-π model
Stacked transformer and power transfer measured up to 94GHz
65-GHz polyphase filter and measured phase response 1-65GHz
34 µm
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 12
Patch Antenna Design
• Patch Antenna Gain: -8.5dBi
• Patch has similar gain as dipole but better isolation on Si
M6 Slotted Patchr = 4.2
M1 Ground Plane
L = 1.14 mm
P+-substrateContacts to substrate
Ground Plane
h
r
1.7mm
Patch
L_Inset = 400µm
Feed
Loc
atio
n
Si Wafer1.
3mm
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 13
Outline
• Motivation• System Overview and Design• Experimental Results• Conclusions• Acknowledgments
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 14
Fabrication Technology
• Jazz Semiconductor’s SBC18 SiGe BiCMOS process
• fT, fMAX >150 GHz
• 6-metal backend
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 15
Fabricated Structures1.7mm
LNA
VCO Output BufferIF
Amp
Mixer
1mm
1mm
1.7mm x 1.3mm Patch Antenna 1.
3mm
1mm
1mm
LNA
VCO
Mixer
IF Amp
Output Buffer
2.5mm x 2.5mm 1mm x 1mm
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 16
2-Stage Cascode LNA Measurements
RF+
RF-
Vb1
3.3V
RF In
Vb2
Vb3 Vb4
Patch Antenna
LNA
Microstrip Feedline
To Mixer
• Breakout measurements:
14dB S21 @ 65GHz
Input P1dB = -12.8dBm
• Simulated NF = 10.5dB
• 40mW from 3.3V supply
• Total Area: 370 x 480µm2
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 17
• on-wafer probing of sensor without on-chip antenna• measurement using horn antenna/suspended probe
and adjustable metal reflector
Experimental Results
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 18
Experimental Results
• SE meas. with external RF input of -48dBm @ 64GHz
• SE down-conversion gain of 16.5dB
• SE transmit output spectrum• Diff. output power +4.3dBm
after de-embedding set-up loss
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 19
• 6 elevations of horn antenna over Rx patch antenna (~ 15mm - 100mm)
• Propagation loss contributes to loss in conversion gain
Experimental Results
• 16.5dB w/o antenna• -24.5dB suspended probe
over antenna• -26dB horn antenna over
patch antenna
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 20
Experimental Results
Gain in good agreement with spectral measurement
Measured IIP3 = -20dBm
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 21
Performance Summary
Rx conversion gain (on-wafer probed)
16.5dB (S)
Rx conversion gain (horn antenna) -26dB (S)
Rx conversion gain (suspended probe)
-24.5dB (S)
Rx IIP3 -20dBm
Rx P1dB, in -30dBm
Rx noise figure (min.) 12.5dB
Tx output power (@ 65GHz) 1.3dBm (4.3dBm D)
LO tuning range 61-67GHz
Power consumption 640mW
Area 1 x 1mm2 (no patch antenna)2.5 x 2.5mm2 (with patch
antenna)S: Single-ended D: Differential
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 22
Conclusions
• Single-chip 65-GHz Doppler sensor featuring:
61-67GHz integrated varactor-tuned fundamental frequency VCO
on-chip patch antenna
extensive use of lumped passives to minimize chip area
• Chip demonstrates:
high level of mm-wave integration achievable in today’s production silicon technology
feasibility of low-cost mm-wave systems for sensor and radio applications
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 23
Acknowledgments
• NSERC and Micronet for financial support
• Jazz Semiconductor for fabrication
• CMC for CAD tools
• K. Tang, K. Yau and S. Shahramian at U of T for simulation and measurement support
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 24
Thank You.
Questions…
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 25
Backup Slides
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 26
System Design Considerations
• System acts as speed and motion sensor according to the Doppler effect:
f
cfv d
2
1target
targetreturn2
1vtDist
• Range of detectable speeds dependent on Doppler freq. shift
Upper bound set by IF amplifier BW
Lower bound set by VCO phase noiseP
min
Log(IF)10kHz 10MHz
Sensitivity
Phase Noise -20dB/dec
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 27
Building Blocks: On-Chip VCO• Integrated 61-67GHz VCO
• Frequency scaled from earlier 60-GHz design by C. Lee (CSICS, ’04) with phase noise of -104dBc/Hz @ 1MHz carrier offset
• Differential Colpitts configuration with accumulation mode nMOS varactor (C2) and inductive emitter degeneration (LE) for wide tuning range, low phase noise
Bbe
m RCCCω
gR
212 )(
Vdd = 4V
Vtune
C1
C2 C2
LB
LE
LEE L
EE
LE
C1
Vdd
Vbb
LO+ LO-
LB
21
21
)(
)(,
2
1
CCC
CCCC
CLf
be
beEQ
EQtank
osc
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 28
System Design Considerations
Why Patch Antenna?• Low profile planar configuration ease of integration• Can be accurately designed and analyzed using transmission-line
model • Metal ground plane and substrate contacts help maximize isolation,
reduce coupling into substrate
Ground Plane
Patch
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 29
Simulated Antenna Gain Results
65-GHz Doppler Sensor with On-Chip Antenna in 0.18um SiGe BiCMOS 30
Lowest Horn Antenna Elevation
Highest Horn Antenna Elevation
Radar Measurement Setup