EXPERIMENTAL INVESTIGATION OF THE POST MOUNT STRUCTURE IN WAVE-GUIDE-TYPE SIS MIXERS

A x70 scale model for a W-band waveguide-type SIS mixer mount has been fabricated and employed to investigate the 'post mount' structure, th at is, a planar structure (on the quartz substrate) located in the wav eguide for mounting an SIS junction (array). To collect accurate imped ance data for the simulation of the equivalent circuit model of the 'p ost mount', a novel measurement technique is proposed. The equivalent lumped parameters have been extracted for various configurations of th e 'post mount', by fitting the measured RF impedances. Their dependenc ies on the boundary condition under which the 'postmount' is located, are examined through several simulations based on the finite element m ethod. Finally, the embedding impedances of the scaled mixer mount are calculated in terms of the established equivalent circuit model of th e 'post mount', and are compared with those calculated by the Eisenhar t-Khan model.