A D-band SPST switch using parallel-stripline swap with defected ground structure

Abstract

In this paper, we propose a D-band switch design using a parallel-stripline swap hybrid coupler with defected ground structure (DGS). Compared to the conventional transmission line (TL) with high insertion loss at high frequency, the equivalent capacitance introduced by the coupler gap leads to series resonance condition which results in lower insertion loss at the higher frequency. The hybrid coupler enables two additional degrees of design freedom since the capacitance and inductance can be tuned by the structural dimension of the coupler. The fabricated switch with core area of 0.0036 mm2 shows measured insertion loss of 1.6–3 dB from 110–134 GHz, return loss of higher than 10 dB and isolation level around 16 dB.