A 120–150 GHz Power Amplifier in 28-nm CMOS Achieving 21.9-dB Gain and 11.8-dBm P_sat for Sub-THz Imaging System

Abstract

This paper presents a high-gain D-band power amplifier (PA) fabricated with 28-nm CMOS technology for a sub-terahertz frequency modulated continuous wave imaging system. It adopts two-channel power combining using artificial transmission lines to absorb the parasitic capacitance of the ground-signal-ground pad. The layout of the transistors and neutralization capacitors are optimized to improve the maximum stable gain, stability, and robustness. Asymmetrically magnetically coupled resonators are used in inter-stage and input matching networks to extend the operating bandwidth. The PA achieves a peak power gain of 21.9 dB and maximum output power of 11.8 dBm with 10.7% of power-added efficiency. Also, this PA can achieve higher than 10 dBm output power over the frequency range of 120–150 GHz.

Keywords

• D-band
• power amplifier (PA)
• sub-terahertz (sub-THz)
• CMOS
• power combining
• imaging system