Above 200 GHz On-Chip CMOS

Frequency Generation, Transmission

and Receiving

Bassam Khamaisi

and

Eran Socher

Department of Physical Electronics

Faculty of Engineering

Tel-Aviv University

• Background and Motivation

• Signal Generation at 209-233 GHz

• Circuit topology

• Fundamental generation

• 3rd harmonic generation

• 3rd harmonic extraction

• Measurement results

• Signal Transmission at 210-227 GHz

• Transmitter characterization

• Full CMOS Imaging System at 220 GHz

• Receiver at 270 GHz

Outline

Motivation and Application

Sub-MMW MMW

Spatial Resolution

Material Transmission

Applications

Homeland security

detection of explosives

www.Teraview.com 3 3

Tumor Detection

THz gap – working at sub-MMW or THz currently relies on either

multiplying RF/mm-wave III-V-based sources or mixing optical

sources.

Component and system cost.

D. Huang et al, IEEE JSSC, vol. 43, pp. 2730-2738, 2008.

Why are Sub-MMW Systems Challenging?

Challenges to Sub-MMW Systems Based on CMOS

Why CMOS?

• CMOS is promising technology due to

1. Low cost 2. High level integration

CMOS challenges on sub-MMW

• The main challenge is signal generation with:

1. High output power 2. Wide tuning range

• Limitation of power amplification at sub-MMW band.

• Most of reported signal sources on CMOS suffer from low power and

frequency bandwidth.

E. Seok et al, ISSCC Dig. Tech. Papers, p.472 , 2008.

Signal source at 410GHz

• Power about 15nW and tuning range of 3GHz (0.73%).

• Not sufficient for practical applications.

Challenges to Sub-MMW Systems Based on CMOS

Harmonics approach:

• Generating frequencies beyond the process fmax by using

higher harmonics of a fundamental MMW CMOS source.

• Advantages:

1. Improved frequency tuning (done at fundamental).

2. Exploiting the transistor non linearity to generate

powerful signals beyond fmax.

Proposed Approach: Using Harmonics

Signal source based on differential Colpitts VCO

GND

Vg

Vdd

S

G

G

390 µ

m

440 µm

GND

Vg

Vdd

S

G

G

GND

Vg

Vdd

S

G

G

390 µ

m

440 µm

Signal Source at 209-233GHz

•Signal source based on differential Colpitts VCO

Fundamental generation

3rd harmonic generation

3rd harmonic coupling

•This topology achieves at fund:

1. Wide tuning range.

2. High output power.

(Electronic Letters, Socher and Jameson, 2011)

Several roles for the transistors:

• Introduce negative resistance to compensate tank loss.

•Buffer stage between tank and load.

•Frequency tuning by controlling bias point.

•Power matching to load stage.

Signal Source at 209-233GHz

Barkhausen criteria

0ReRe resactive ZZ 0ImIm resactive ZZ

Signal Source- Oscillation Analysis

Resonance Oscillation start-up

Signal at output Output spectrum

Gate signal

Fundamental generation

Signal Source- Oscillation Analysis

Fundamental generation

Transistor i-V model

0

0

gs t gs t

ds

k V V V VI

else

00

1

cos2

gs tV V

V

0 0

1 0

cos

2 2cos2

0

ds

kVI

else

0 1 2 3( ) cos cos2 cos3dsI I I I I

Due to inherent transistor

non-linearity:

Gate voltage

Drain current

0

tV 1V

0I

0

t

t

Signal Source- Amplitude Behavior Model

13

Fundamental generation

1

0 0

1

sin2

M

I kG

V

out

T

in

VX

I

00 ( )

( ) 1T T

l M T M TX s j RA s j G X G R

1M

T

GR

0

eff

T

eff

QR

C

RT describes the real trans-resistance

The tank trans-impedance

The large signal trans-conductance:

In oscillation, the open loop gain at SS

Signal Source- Amplitude Behavior Model

14

Fundamental generation

11 0 0sin

2

kVI

Fundamental current Fundamental voltage

Signal Source- Amplitude Behavior Model

15

3rd harmonic generation

1 03 0

sin1 cos

6

kVI

3rd harmonic current

A sufficient current magnitude in the 3rd harmonic.

MG

Signal Source- Amplitude Behavior Model

XF modeling

Transformer XF challenges:

1. Providing high enough impedance to

generate powerful fundamental and create

a significant 3rd harmonic current.

2. Coupling the 3rd harmonic to the load.

GND

Vg

Vdd

S

G

G

39

0 µ

m

440 µm

GND

Vg

Vdd

S

G

G

GND

Vg

Vdd

S

G

G

39

0 µ

m

440 µm

XF 3D layout

IN

Out

XF

Transistors

drains

Load

Signal Source- Transformer

3rd harmonic coupling

Signal Source- Transformer

XF equivalent model

Single ended transformer

3rd harmonic coupling by parasitic capacitor.

_

3

01

1

1

a

XF S

p

sLs

NZ

ssC N

_

3

1

1.2XF S

p

Zs C

Fundamental tone of signal source around 75GHz

Pout = -2dBm @ 75GHz

Phase noise = -91.15 dBc/Hz @ 1MHz Offset

GND

Vg

Vdd

S

G

G

390 µ

m

440 µm

GND

Vg

Vdd

S

G

G

GND

Vg

Vdd

S

G

G

390 µ

m

440 µm

Signal Source- Measurement

0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2

210

215

220

225

230

235

Freq

uen

cy

[G

Hz]

Vg [V]

Vdd

=1.2V

Vdd

=1.4V

Vdd

=1.6V

Vdd

=1.8V

205 210 215 220 225 230 235

-30

-25

-20

-15

-10

-5

Vdd

=1.2V

Vdd

=1.4V

Vdd

=1.6V

Vdd

=1.8V

Ou

tpu

t p

ow

er [

dB

m]

Frequency [GHz]

Tuning range=24GHz (10.6%) Maximum output power ≈ -6.2dBm

Signal Source at 209-233GHz

B. Khamaisi and E. Socher, IEEE MCWL, Vol. 22, No. 5, 2012.

GND

Vg

Vdd

S

G

G

390 µ

m

440 µm

GND

Vg

Vdd

S

G

G

GND

Vg

Vdd

S

G

G

390 µ

m

440 µm

Comparison of state of the art sources above 200GHz

[1] [2] [3] [3] This

work

Ref.

Super-

position

Funda

-mental

Triple-

Push

Triple-

push

3rd

Harmonic

generation

Type

90 nm

CMOS

InP 65 nm

CMOS

0.13µm

CMOS

90 nm

CMOS

Tech.

324 254 482 256 228 Freq.

[GHz]

-46 -8 -9 -17 -6.2 Output power

[dBm]

4 NA NA NA 24 Tuning Range

[GHz]

-78

(est.)

NA -76 -88

(est.)

-90.5

(est.)

PN

@ 1MHz

offset

[dBc/Hz]

0.0378

*

0.16 0.0303 0.052 0.1716 Chip size

[mm2]

12 11.7 27.5 71 77.4 DC power

[mW]

Signal Source at 209-233GHz

References

[1] D. Huang, T. R. LaRocca, M. C. F. Chang, L. Samoska, A. Fung, R. L. Campbell, and

M. Andrews, "Terahertz CMOS Frequency Generator Using Linear Superposition

Technique," Solid-State Circuits, IEEE Journal of, vol. 43, pp. 2730-2738, 2008.

[2] V. Radisic, X. B. Mei, W. R. Deal, W. Yoshida, P. H. Liu, J. Uyeda, M. Barsky, L.

Samoska, A. Fung, T. Gaier, and R. Lai, "Demonstration of Sub-Millimeter Wave

Fundamental Oscillators Using 35-nm InP HEMT Technology," Microwave and Wireless

Components Letters, IEEE, vol. 17, pp. 223-225, 2007.

[3] O. Momeni and E. Afshari, "High Power Terahertz and Millimeter-Wave Oscillator

Design: A Systematic Approach," Solid-State Circuits, IEEE Journal of, vol. 46, pp. 583-

597.

Signal Source at 209-233GHz

Signal Generation and Transmission

• Signal source at 209-233GHz

• Transmitter at 210-227GHz

GND

Vg

Vdd

S

G

G

39

0 µ

m

440 µm

GND

Vg

Vdd

S

G

G

GND

Vg

Vdd

S

G

G

39

0 µ

m

440 µm

Signal Generation

Signal Transmission

Transmitter at 210-227GHz

Transmitter Characterization

B. Khamaisi, S. Jameson, and E. Socher, IEEE T-TST, vol. 3, 2013.

Transmitter power

on-top at 217GHz (at 4mm distance)

Measurement

-45

-40

-35

-30

-25

-20

205 210 215 220 225 230

Freqeuncy [GHz]

Dete

cte

d p

ow

er [

dB

m]

-22.5

-17.5

-12.5

-7.5

-2.5

2.5

EIR

P [

dB

m]

Transmitter Characterization

Detected power on-top at 217GHz

(at 4mm distance)

2

eff

RX πR4A

PEIRP

Frequency drop of 13% between

simulation and measurement.

Measured maximum EIRP= +1.8dBm

B. Khamaisi, S. Jameson and E. Socher, IEEE T-TST, vol. 3, 2013.

Comparison of state of the art transmitters above 200GHz

[1] [2] [1] This

work

This

work

Ref.

Push- Push

VCO

Cross coupled

push-push

VCO

Cross coupled

push-push VCO

Colpitts VCO

and 3rd Harm.

Gen

Colpitts VCO

and 3rd Harm.

Gen

Signal source

type on TX

130nm

SiGe

65nm

CMOS

65nm

CMOS

90nm

CMOS

90nm

CMOS

Tech.

170 191.2 300 217 217 Freq. [GHz]

- 11 10 10.6 13.1 Directivity

[dB]

- -1.9 -1 +1.8 +2.8 EIRP [dBm]

- - -12.7

-

-8.8 -10.3 PT_Rad [dBm]

- 3.6 - 17 17 T.R. [GHz]

- 1.1 0.64 0.531 0.531 TX chip size

(with pads)

[mm2]

- 77 75 122 134 PDC [mW]

-

- - 280 80 Si bulk

[µm]

Transmitter at 210-227GHz

References

[1] E. Laskin, P. Chevalier, A. Chantre, B. Sautreuil, and S. P. Voinigescu, “165-GHz Transceiver

in SiGe Technology,” IEEE JSSC, vol. 43, pp. 1087-1100, 2008.

[2] K. Sengupta and A. Hajimiri, “Sub-THz beam-forming using near-field coupling of Distributed

Active Radiator arrays,” in IEEE RFIC, pp. 1-4, 2011.

[3] K. Sengupta and A. Hajimiri, “Distributed active radiation for THz signal generation,” in IEEE

ISSCC, pp. 288-289, 2011.

Transmitter at 210-227GHz

Full CMOS Imaging System at 220GHz

A. Lisauskas, B. Khamaisi, S. Boppel, M. Mundt, V. Krozer, E. Socher and H. G. Roskos, IRMMW-THz, September 2012.

Imaging System at 220GHz Optical Image

220 GHz Power Transmission

Receiver

Transmitter

Receiver at 270 GHz

• 65 nm CMOS (fmax ≈ 210 GHz )

• On-Chip LO

• LO based 3rd harmonic generation

• Mixer: single transistor

• Chip size: 470 µm x 470 µm

Simulations

VgLO [V]

CG

[d

B]

S1

1 [

dB

]

Freq. [GHz]

VdLO=2.0 V

VdLO=1.8 V

VdLO=1.6 V

Thank You !