Highly Efficient WR4 Signal Sources and Transceiver for CW Radar Applications

This paper presents two fundamental-wave oscillator realizations, a fixed-frequency (V1) and a tunable (V2) option, operating above 200 GHz for monostatic continuous-wave (CW) radar sensing. Fabricated in a 90 nm SiGe BiCMOS process, the oscillators achieve high output power and good efficiency. V1 operates at 202.5 GHz with an output power of 4.9 dBm and a DC-to-RF efficiency of 3.68%. V2 tunes over a 2.8 GHz range around 228.8 GHz with an output power of 4.5 dBm and a DC-to-RF efficiency of 3.36%. Based on both oscillator versions, monostatic I/Q radar transceivers were designed. Precise Doppler radar measurements were conducted successfully up to 150°C chip temperature which demonstrates the capability for robust fundamental-wave signal sources even at high temperatures.