U-band wideband receiver front-end

Abstract

A 40-60 GHz wideband receiver front-end, consisting of a two-stage low noise amplifier (LNA) and a downconverter, is presented. The downconverter comprises a subharmonic mixer with a pair of anti-parallel diodes in asymmetric bilateral finline, and a local oscillator (LO) doubler-amplifier chain to provide the necessary LO power to the subharmonic mixer. Thus the U-band front-end operates with a LO frequency range of 10-15 GHz. The circuits are fabricated on 254 mum thick Rogers Duroid 5880 substrate in hybrid integrated circuit technology. Measurement results show the gain of LNA is around 24 dB, the conversion loss of the downconverter is in the range of 8-15 dB, and the front-end has a conversion gain greater than 6 dB over the range of 40-60 GHz.