A 140-GHz quad-receivers IC and sub-assembly for compact passive imaging sensors

A CPW-MMIC (coplanar-waveguide monolithic microwave integrated circuit) with quad-channel receiver IC for 140-GHz passive millimeter-wave imaging system was developed. The IC has four low-noise amplifiers (LNA), Dicke switches, and detectors using Schottokey barrier diode. The Dicke switch has 1dB insertion loss and 8 dB on-off ratio. The LNA has 40 dB gain and 5 dB noise figure. The total power consumption of the IC is 0.39 W. The IC was assembled with a four-antenna array fabricated on a polyimide film. The antenna typically has 9 dB antenna gain and 5 dB loss. This subassembly has a print board connector, therefore we can mount four channel receivers as desired number on the print board easily. The subassembly was finally implemented in 140-GHz imaging system and we confirmed human can be detected at 30 m apart from the imaging system.