A 210 GHz, Subharmonically-Pumped Active FET Mixer MMIC for Radar Imaging Applications

A conversion loss of 8.5 dB is achieved for down-conversion of a 210 GHz RF signal in a sub-harmonically pumped mixer MMIC. The active FET mixer, realized in a 100 nm gate length metamorphic HEMT process, employs a dual-gate topology. The mixer achieves a 3-dB RF bandwidth from 188 to more than 210 GHz and is driven by a 10 dBm subharmonic LO signal. The combination with an integrated source follower stage results in a 2 GHz IF bandwidth. The mixer is dedicated to active imaging systems for concealed weapon detection operating in the atmospheric window around 220 GHz.