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-signalground 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.INDEX TERMS D-band, power amplifier (PA), sub-terahertz (sub-THz), CMOS, power combining, imaging system, frequency modulated continuous wave (FMCW).
The fifth‐generation (5G) mobile communication system is being developed to provide ultra‐high‐speed and large‐capacity wireless communication services. However, due to the large transmission loss in the air for high‐frequency signals, it is necessary to use large‐scale array antennas to achieve adaptive control of antenna directivity to compensate for the loss. This paper reports a passive phase shifter operating at 23–28 GHz. The proposed 5‐bit switch‐type phase shifter with 1‐bit calibration is designed in a 0.15‐μm GaAs process. A new design method based on the optimized ABCD matrix and impedance matching techniques between a chip and a printed circuit board (PCB) is developed to obtain better radio‐frequency (RF) signal transmission. The proposed phase shifter features a good‐phase performance with a measured root‐mean‐square (RMS) phase error of less than 10° across 23–28 GHz. For all the phase shift states, the insertion loss is 18 ± 2 dB at 28 GHz and the RMS gain error is less than 2.1 dB over 23–28 GHz including pads and RF connector loss. The phase shifter consumes no DC power and occupies a chip area of 2 × 0.7 mm2 including all the pads.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.