A 320–360 GHz Sub-Harmonically pumped Image-Rejection Mixer for earth observation applications

We report on the development of a 320-360 GHz sub-harmonically pumped image-rejection mixer (SHIRM). The device incorporates two anti-parallel pairs of planar Schottky diodes flip-chip mounted onto a single quartz-based microstrip circuit. Measurements provide a best SSB receiver noise temperature of 3300 K and a side-band ratio between 7.2-23.2 dB over the RF bandwidth. This is the first time that the operation of a Schottky diode-based image-rejection mixer has been demonstrated at these frequencies.