Th2G-3

A Power Efficient BiCMOS Ka-Band

Transmitter Front-End for SATCOM

Phased-Arrays

S. Rasti-Boroujeni, A. Wyrzykowska, M. Mazaheri, A. Palizban, S. Ituah, A. El-Gouhary, G. Chen, H. Gharaei-

Garakani, M. Nezhad-Ahmadi, S. Safavi-Naeini

University of Waterloo, Waterloo, Canada

Student

Paper

Finalist

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• Motivation and Background

• Proposed Solution

• Circuit Implementation

• Measurement Results

• Conclusion

2

Outline

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Mobile SATCOM

Courtesy of Telesat

• Broadband in-flight internet access.

• Hundreds of satellite form a constellation at LEO for a global

connectivity.

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• Fast Beam-Steering

• Conformal and Low Profile

• Polarization Control

• Controlled Radiation Mask

• Affordable Power Consumption

4

Mobile SATCOM Requirements and

Challanges

VS

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• More than 4000 dual-polarized antenna elements is

needed.

• Power consumption of existing SATCOM beam-former

solutions > 500-700 W

• Our Goal is to reduce the power consumption to below

200 W for a 4000 elements dual-polarized array for 48

dBW EIRP.

5

Motivation and Background

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• Modular phased array configuration is a highly flexible

and cost-effective solution for large phased arrays.

• 1024 elements active phased arrays is developed with

this method [1].

6

Modular Scalable Phased Arrays

2 cm

2 cm

[1] W. M. Abdel-Wahab et al., "A Modular Architecture for Wide Scan Angle Phased Array Antenna for K/Ka Mobile SATCOM," 2019

IEEE MTT-S International Microwave Symposium (IMS), Boston, MA, USA, 2019, pp. 1076-1079

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Summary of CIARS Active Phased Array

Development

This Work

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Circuit Implementation

• GF-BiCMOS 0.13 µm with ft / fMax of 250/340 GHz is used.

• The TX channel is designed for a 4000 elements phased-array

antenna. OP1dB=11dBm

• The architecture is designed for independent amplitude and phase

shift control.

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Circuit Implementation

-2 to -17 dB

Gain Control

-4 dB

1-bit phase

inverter

16 dB

Fixed Gain

Stage

-9 to -7 dB

Reflective

Type Phase

Shifter

23 dB-38%

Peak PAE

Two Stage

Power Amplifier

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Measurement Results-Small Signal

• 3dB bandwidth from 27.5 to 31.5 GHz

• 15 dB gain control

• ± 5 degree phase error

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Measurement Results-Small Signal

• 200 degree continuous phase control.

• 1-bit 180 degree phase inverter.

• ±1.1 dB amplitude variation @ 30 GHz

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• Amplitude-Phase variation over the bandwidth.

12

Measurement Results-Small Signal

27 GHz 28 GHz 29 GHz 30 GHz

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Measurement Results-Large Signal

• TX channel PAE and P1dB over frequency at nominal

supply voltage of 1.8 V

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Measurement Results-Large Signal

• Thousands of elements operate in deep back-off in

large phased arrays.

• Adaptive supply is used to enhance the efficiency at

back-off.

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• 12% average efficiency for a 300MS/s 64QAM signal at 30

GHz.

15

Measurement Results-Large Signal

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Technology PackageN

Channels

Freq.

(GHz)

𝑷𝟏𝒅𝑩/𝑷𝒔𝒂𝒕(𝒅𝑩𝒎)

Gain

(dB)

𝑷𝑫𝑪/𝑪𝒉.

(mW)

PAE

@ 𝑷𝟏𝒅𝑩

Gain Control

(dB)

Phase

Res.

This Work

U-Waterloo

130nm-

SiGe8xp- 1-TX 27-31 10.8/12 23 45 26.7 15

Continu

ous

Anokiwave - QFN 8-TX27.5-

3012/- 22 112.5 14 32x0.5 5 bits

Anokiwave - WLCSP 8-TX27.5-

318/- 20 - - 32x0.5 6 bits

University of

Ulm

250nm-SiGe- 2TX-1RX

29.5-

30.8

12.9/15

.337.7 81 19.5 30 8 bits

Qualcomm 28nm-CMOS - 24-TRX26.5-

29.512/14 44 122 13 8x1 3 bits

Qualcomm -

TAMU40nm-CMOS - 1-TRX 27-30 14.6/15 12.4 137 21 9x1 3 bits

IBM130nm-

SiGe8hp- 32-TRX

27.2-

28.713.6/16 30 144 15.9 8x1 5 bits

UCSD 180nm-SiGe - 4-TRX 28-32 11/13 19 220 5.7 20 6 bits

16

Performance ComparisonS

AT

CO

M5

G

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• A power-efficient RF front-end for Ka-Band SATCOM

phased array transmitter is presented.

• Peak PAE of 27% is achieved for OP1dB of 11.5 dBm.

• 400 degree phase and 15 dB gain control is achieved.

• Adaptive supply is employed to enhance efficiency.

• Achieving 200 W of DC Power for a 4000 elements array

is feasible with the implemented solution.

17

Conclusion

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Thanks for Your Attention!

soroush.rasti@uwaterloo.ca