A quasi-optical subharmonically-pumped receiver using separately biased Schottky diode pairs

A novel quasi-optical planar subharmonically pumped receiver including a log-periodic antenna and an anti-parallel Schottky diode pair with independent bias is presented. The antenna and Schottky diode pair have a 20 /spl mu/m and 2.5 /spl mu/m wide split, respectively, for biasing considerations and an overlay capacitor for RF coupling. Millimeter-wave measurements at 91 GHz show that, at /spl plusmn/0.4 V bias, the separately biased subharmonic mixer requires 2-3 times less LO power than the zero-biased subharmonic mixer for the same 8 dB (SSB) conversion loss. At 180 GHz a similar LO power requirement reduction has been achieved, with a minimum conversion loss of 9.7 dB and noise temperature of 1850 K (DS8). >