sub-thz wireless communication & sensing a perspective on ... · • a 240-ghz transceiver...

Sub-THz Wireless Communication & Sensing – A Perspective on Device, Circuit, and System

Hua Wang

Associate Professor

School of ECE, Georgia Tech

Ned Cahoon

RF Business Development

GLOBALFOUNDRIES

Anirban Bandyopadhyay

RF Business Development

GLOBALFOUNDRIES

Outline

• Overview of a few Sub-THz applications and Technical challenges

• Status of Power Amplifier capabilities on different Semiconductor platforms

• Examples of System level performance for different sub-THz applications

• State-of-the-art capabilities of different Silicon Technologies and roadmap

• Summary

System Applications in Sub-THz Frequency Bands

• Imaging [T. Chi, et al, ISSCC, 2017.]

Super High Resolution and Hyperspectral

• Spectroscopy

High Sensitivity and Molecular Signature

• Communication [S. Lee, et al, ISSCC, 2019.]

Extremely High Data-Rate

• Radar

Super High Resolution and 3D Imaging

[C. Wang, et al, ISSCC, 2017.]

16 QAM / 80Gb/s

GHz

EVM=12% rms

[J. Grzyb, et al, TTST, 2016.]

Major Technical Challenges

• Challenge 1

Signal Propagation: Path loss at sub-THz

• Challenge 2

Device Capabilities: Limited gain, power density, Pout, and NF

• Challenge 3

Array Pitch Size: Small element pitch for 2D arrays (λ/2=625µm at 240GHz)

• Challenge 4

Systems/Circuits: Limited gain, power density, freq. Nonlinear circuits

Array, Lens or

“Powerful” Devices

Performance/

Functionalities

vs. Integration

Energy Efficiency

vs. Spectrum

Efficiency

vs. Spectrum BW

H. Wang, et al., "Power Amplifiers Performance Survey 2000-Present," [Online]. Available: https://gems.ece.gatech.edu/PA_survey.html

Power Amplifier Survey (2000-present) by Georgia Tech GEMS Group

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Psa

t (d

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(Log) Frequency (GHz)

Saturated Output Power vs. Frequency (All Technologies)

CMOS

SiGe

GaN

GaAs

LDMOS

InP

Oscillators

Multipliers

Johnson’s Limit


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CMOS

SiGe

GaN

GaAs

LDMOS

InP

Oscillators

Multipliers

GaN 150nm

(Fmax=110GHz)

SiGe 130nm

(Fmax=340GHz) CMOS 45nm

(Fmax=390GHz)

InP 250nm

(Fmax=750GHz)


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Psa

t (dB

m)

Frequency (GHz)


CMOS

SiGe

GaN

InP

InP 250nm

(Fmax=750GHz)

SiGe 130nm

(Fmax=220GHz)

CMOS 45nm

(Fmax=280GHz)

GaN 150nm

(Fmax=110GHz)

• Output power vs. frequency

• Power generation scheme vs. frequency

• Power amplifiers and Fundamental

Oscillators (~200GHz)

• Multipliers and Harmonic Oscillators

(~500GHz and above)


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Psa

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CMOS Power Amplifiers SiGe Power Amplifiers

Oscillators Multipliers

Johnson’s Limit


fT and fmax of Existing Device Technologies

Teledyne InP 130nm(fmax=1.1THz)

Teledyne InP 250nm(fmax=750GHz)

Keysight InP 500nm(fmax=550GHz)

Qorvo GaN 150nm(fmax=110GHz)

III-V Technology

𝑓𝑇 =𝑔𝑚

2𝜋𝐶𝑔𝑔• fT cut-off frequency: Transistor short-circuit ac current gain falls to 1

Switching circuits MUX/dividers and low noise circuit LNA

• fmax max oscillation frequency: Transistor maximum unilateral power

gain falls to 1 Power amplifiers, LNAs, general amplifiers, oscillators 𝑓𝑚𝑎𝑥 ≈

𝑓𝑇8𝜋𝑅𝑔𝐶𝑔𝑑

• Amplifier design Rule of Thumb: Frequency f<fmax/2 with ~6dB gain for perfectly neutralized devices

Squeezing More Power Gain from Devices

[H. Bameri, et al, “A High-Gain mm-Wave Amplifier Design: An Analytical Approach to Power Gain Boosting,” JSSC, 2017.]

[S.J. Mason, et al, “S.J. Mason, “Power Gain in Feedback Amplifier,” Transactions of the IRE Professional Group on Circuit Theory, 1954.]

𝐺𝑚𝑎 =Y21Y12

(K − K2 − 1)

Maximum available gain:

Maximum stable gain(stabilized device, K=1):

𝐺𝑚𝑠 =Y21Y12

K =2𝑅𝑒 Y11 𝑅𝑒 Y22 − 𝑅𝑒 Y12Y21

|Y12Y21|

Stability factor:

Unilateral power gain(U):

=𝑌21′ 2

4[𝑅𝑒 𝑌11′ 𝑅𝑒 𝑌22

′ ]

𝑈 =Y21 − Y12

2

4[𝑅𝑒 Y11 𝑅𝑒 Y22 − 𝑅𝑒 Y12 𝑅𝑒 Y21 ]

Maximum achievable gain:

𝐺𝑚𝑎𝑥 = 2𝑈 − 1 + 2 𝑈(𝑈 − 1) ≈ 4𝑈

Input

Network

Output

Network

Unilateralized Network

Input

Network

Output

Network

Embedded Network

Input

Network

Output

Network

Basic

Device

Neutralization

Unilateralization:

Broad Band

Embedding:

Narrow Band

Achievable Power Gain in Example CMOS Technology vs. Teledyne 250nm InP

• Device with layout and parasitics extraction

• Basic device vs. Neutralization vs. Embedding (100GHz-300GHz)

• An example CMOS technology (fmax~280GHz) vs. Teledyne 250nm InP (fmax~750GHz)

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10 100 1000

Gai

n(d

B)

Frequency(GHz)

6dB improvement

Near-fmax regionU

Gmax

Gma/Gms

Power Gain of Example CMOS Technology Example CMOS Technology vs. 250nm InP

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10 100 1000G

ain

(dB

)

Frequency(GHz)

UGmax

Gma/Gms

Fmax(280) (750)

GlobalFoudries 45nm CMOS SOI

Teledyne 250nm InP

Example CMOS Technology

Basic Device:

Gma/Gms

Neutralization: U

Embedding: 4×U

Applications and Systems at Sub-THz (Communication)• A 240-GHz transceiver front-end with antenna using IHP SiGe:C SiGe BiCMOS

• TX sat. Pout of -0.8 dBm with optical lens for wireless transmission over 15 cm

• 25 Gb/s BPSK with BER of 2.2×10-4.

[M. Eissa, et al, “Wideband 240-GHz Transmitter and Receiver in BiCMOS Technology With 25-Gbit/s Data Rate,” JSSC, 2018.] Leibniz-Institut für innovative Mikroelektronik, Germany

[S. Lee, et al, “An 80Gb/s 300GHz-Band Single-Chip CMOS Transceiver,” ISSCC, 2019.] Hiroshima University, Japan

• A 300GHz-Band Single-Chip CMOS Transceiver using 40nm CMOS

• Power mixer + double-rat-race 4-way combiner TX sat. Pout of -1.6dBm

• Mixer-first receiver 20dB NF

• 80Gb/s 16QAM over 3cm

Applications and Systems at Sub-THz (Communication)

• A 100GHz-300GHz Continuous-Wave

Hyperspectral Imaging Transceiver

(Globalfoundries 45nm CMOS SOI)

• Transmission mode imaging by step-motor-

controlled 2D translation stage

• Non-contact screening for food safety and 3D

printing products

• Dried and

fresh leaves• Cookie and metal

screw in a

translucent package

[T. Chi, et al, “Packaged 90-to-300GHz Transmitter and 115-to-325GHz Coherent Receiver in CMOS for Full-Band Continuous-Wave mm-Wave Hyperspectral Imaging,” ISSCC, 2017.] Georgia Tech, US

Applications and Systems at Sub-THz (Imaging)

Applications and Systems at Sub-THz (Imaging)

• TX : Broadband 90-to-300GHz distributed quadrupler (DQ)

• RX : Broadband 115-to-325GHz 4th-subharmonic mixer (SHM)

[T. Chi, et al, “Packaged 90-to-300GHz Transmitter and 115-to-325GHz Coherent Receiver in CMOS for Full-Band Continuous-Wave mm-Wave Hyperspectral Imaging,” ISSCC, 2017.] Georgia Tech, US

Applications and Systems at Sub-THz (Radar)• A 145GHz FMCW-Radar Transceiver in 28nm bulk CMOS

• High RF carrier permits greater velocity and MIMO-angular resolution

• A wide RF bandwidth of 13GHz 11mm range/depth resolution

[A. Visweswaran, et al, “A 145GHz FMCW-Radar Transceiver in 28nm CMOS,” ISSCC, 2019.] imec, Leuven, Belgium

TX path:

RX path:

Applications and Systems at Sub-THz (Spectroscopy)• A 220-to-320GHz Spectrometer for Molecular Gas Spectroscopy (65nm CMOS)

• Frequency doubler array + on-chip folded slot antenna array

• 5.2mW Radiated Power and 14.6-to-19.5dB Noise Figure

• Single frequency sweep (e.g. ~3 hours for 100GHz bandwidth)

• Simultaneous scanning using 20 comb lines

(8 minutes for 100GHz bandwidth)

[C. Wang, et al, “Rapid and Energy-Efficient Molecular Sensing Using Dual mm-Wave Combs in 65nm CMOS: A 220-to-320GHz Spectrometer with 5.2mW Radiated

Power and 14.6-to-19.5dB Noise Figure,” ISSCC, 2017.] MIT, US

Frontend Circuits at Sub-THz (Power Generation/TX)

• 215 GHz Harmonic Oscillator in TMSC 65nm CMOS

• Max dc-to-RF efficiency of 4.6% at 215 GHz and max Pout of 5.6 dBm from a

single oscillator

R. Kananizadeh and O. Momeni, "High-Power and High-Efficiency Millimeter-Wave Harmonic Oscillator Design, Exploiting Harmonic Positive Feedback in CMOS," in IEEE

Transactions on Microwave Theory and Techniques, vol. 65, no. 10, pp. 3922-3936, Oct. 2017. UC Davis, US

280µ

m

Frontend Circuits at Sub-THz (Power Geneneration/TX)• 500 GHz Sub-harmonic Oscillator in Globalfoundries 9HP SiGe

• Multi-concentric-ring structure for multi-phase injection-locking multiplier

• Max Pout of -16.6 dBm at 498 GHz with 5.1% freq. tuning and phase noise

of 87 dBc/Hz at 1 MHz offset

T. Chi, J. Luo, S. Hu and H. Wang, "A multi-phase sub-harmonic injection locking technique for bandwidth extension in silicon-based THz signal generation,"

Proceedings of the IEEE 2014 Custom Integrated Circuits Conference, San Jose, CA, 2014, pp. 1-4. Georgia Tech, US

Frontend Circuits at Sub-THz (Regenerative RX and Harmonic Oscillator TX)

Sensitivity (dBm) -89

Max Comm. Distance (cm) 50

Data Rate, Type, BER 4.4Mb/s OOK, 10-7

TX EIRP (dBm) -11.6

PDC (mW) 18.2/31.1 (TX/RX)

[T. Chi, H. Wang, M.-Y. Huang, F. F. Dai, and H. Wang, “A bidirectional lens-free digital-bits-in/-out 0.57mm2 terahertz nano-radio in CMOS with 49.3mW Peak power

consumption supporting 50cm Internet-of-Things communication,” 2018 IEEE Custom Integrated Circuits Conference (CICC), 2018.] Georgia Tech, US

• Harmonic-oscillator TX and Regenerative RX with on-chip TDC for digitized RX outputs •

• Operating at 320GHz using Globalfoundries 45nm CMOS SOI

• On-chip multi-feed slot antenna for on-antenna power combining

CMOS Cut-off Frequency fT

𝐼𝑖𝑛 =𝑉𝑖𝑛𝑍𝑖𝑛

𝐼𝑜𝑢𝑡 = 𝑔𝑚𝑉𝑖𝑛𝐼𝑜𝑢𝑡𝐼𝑖𝑛

= 𝑔𝑚𝑍𝑖𝑛 = 𝑔𝑚1

𝑗𝜔𝑇𝐶𝑖𝑛= 1

⇒ 𝜔𝑇 =𝑔𝑚𝐶𝑖𝑛

𝑓𝑇 =𝑔𝑚

2𝜋𝐶𝑔𝑔

• Transistor speed metric

• Particularly relevant for switching circuits such as MUX/DMUX, dividers, etc

• Definition: Frequency at which short-circuit ac current gain falls to 1

• CMOS fT increases with scaling

Henk M. J. Boots, Gerben Doornbos, and Anco Heringa, “Scaling of Characteristic Frequencies in RF

CMOS,” IEEE Trans. Electron Device, vol. 51, no. 12, pp. 2102-2108, Dec. 2004.

January 12, 2016 GLOBALFOUNDRIES 20

CMOS Maximum Oscillation Frequency fMAX

Conjugate match at the input:

𝑅𝑆 = 𝑅𝑔

⇒ 𝑖𝑖𝑛 = 𝑖𝑖𝑛𝑠 =𝑉𝑆2𝑅𝑔

Conjugate match at the output:𝐺𝑃 =

𝐺𝑜𝑢𝑡𝐺𝑖𝑛

=

12𝑖𝑜𝑢𝑡2 𝑅𝑜𝑢𝑡

12𝑖𝑖𝑛2 𝑅𝑖𝑛

=1

4

𝑖𝑜𝑠𝑖𝑖𝑛𝑠

2𝑅𝐿𝑅𝑔

=1

4

𝑓𝑇𝑓

2𝑅𝐿𝑅𝑔

𝐺𝑃 = 1 ⇒ 𝑓𝑚𝑎𝑥 =1

2𝑓𝑇

𝑅𝐿𝑅𝑔

∴ 𝑓𝑚𝑎𝑥=𝑓𝑇

2 𝑔𝑑𝑠𝑅𝑔 + 2𝜋𝑓𝑇𝑅𝑔𝐶𝑔𝑑𝑍𝑜𝑢𝑡 =1

𝑔𝑑𝑠 +𝑔𝑚𝐶𝑔𝑑

𝐶𝑔𝑠 + 𝐶𝑔𝑑

=1

𝑔𝑑𝑠 + 2𝜋𝑓𝑇𝐶𝑔𝑑

𝑓𝑚𝑎𝑥 ≈𝑓𝑇

8𝜋𝑅𝑔𝐶𝑔𝑑

Scaling of 𝑓𝑚𝑎𝑥depends on 𝑓𝑇, 𝑅𝑔, and 𝐶𝑔𝑑

𝑍𝑖𝑛 = 𝑅𝑔 +1

𝑗𝜔𝐶𝑔𝑠≈ 𝑅𝑔

𝑅𝐿 = 𝑍𝑜𝑢𝑡

• Transistor speed metric

• Particularly relevant for circuits that generate power such as LNA’s, PA’s,

VGA’s, etc

• Definition: Frequency at which the maximum unilateral power gain equals 1

• Parasitics have a larger impact at smaller dimensions, which limits fMAX in

advanced CMOS nodes.

M. Dehan, Characterization and modeling of SOI RF integrated components, Presses univ. de Louvain, 2003.M. Golio, The RF and MIcrowave Handbook, CRC Press Book, 2010.

January 12, 2016 GLOBALFOUNDRIES 21

CMOS fMAX peaks at ~ 450GHz

22

• Advanced nodes struggle with

gate and interconnect resistance

• Peak fMAX achieved in the 32nm

– 22nm nodes

H. J. Lee et al, “Intel 22nm FinFET (22FFL) Process Technology for RF and

mmWave Applications and Circuit Design Optimization for FinFET

Technology“, IEDM 2018

23

SiGe fT, fMAX

• fT improves with vertical scaling f • fMAX improves with reduction in

dominant parasitics

BB

T

MAXCR

ff

8

• Reduce Ccb intrinsic and extrinsic base

capacitance while maintaining low base

resistance

• Reduce Rb extrinsic and intrinsic

resistances while maintaining narrow

base width

January 12, 2016 GLOBALFOUNDRIES

Advances in SiGe have reached 500GHz fT / 700GHz fMAX

24GLOBALFOUNDRIES CONFIDENTIAL

130nm90nm55nmBipolar only

~peak fmax for SOI/CMOS

Published SiGe HBT fT, fMAX hardware results

H. Ruecker and B. Heinemann, “High Performance SiGe HBT

BiCMOS Technology”, RFIC 2018 WMM-5 Workshop

European Consortia for Advanced SiGe Development

• Four projects funded by EU for over a decade

• Significant achievement in both pushing SiGe HBT performance and BiCMOS integration

• DOT5, 2008 – 2010, 500GHz SiGe HBT

• RF2THZ, 2011 – 2014, 55nm SiGe BiCMOS

• DOT7, 2012 – 2016, 700GHz SiGe HBT

• TARANTO, 2017 – 2020, 700GHz SiGe HBT, 130-28nm SiGe BiCMOS

25

Amplifier Power and Gain at 250GHz with 500GHz SiGe

26

M. Eissa and D. Kissinger, “A

13.5dBm Fully Integrated

200-to-250GHz Power

Amplifier with a 4-Way Power

Combiner in SiGe:C

BiCMOS”, ISSCC 2019

27

Summary

• Sub-THz applications reviewed

• Communications – higher data rate

• Radar – higher resolution

• Imaging – high resolution and hyperspectral

• Spectroscopy – high sensitivity and molecular signature

• Challenges for device, circuit and systems at sub-THz frequencies

• Signal propagation and path loss at sub-THz

• Device and circuit issues – limited gain, power density, Pout, NF

• Array pitch size

• Semiconductor technology

• Higher ft/fmax technology needed for sub-THz

• fmax > 2x f application rule of thumb

• CMOS fmax limited by parasitics (gate, interconnect R) for advanced node CMOS

• SiGe demonstrated path to 500GHz/700GHz ft/fmax

• Initiatives in US and Europe for development of 700GHz SiGe BiCMOS technology

sub-thz wireless communication & sensing a perspective on ... · • a 240-ghz transceiver...

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