Investigations on the rectangular waveguide to SIW transition for terahertz applications

Abstract

In this paper, the performance of a terahertz rectangular waveguide to substrate integrated waveguide (SIW) transition using fin line coupling structure is investigated. Two prototypes working at 140 GHz and 180 GHz frequency bands are both designed, and fabricated by using the low‐cost printed‐circuit‐board (PCB) technology. Full‐wave simulations have been used to synthesize and optimize the transitions. In order to evaluate effectively the insertion loss of the transition, three different lengths of transitions are designed and measured for D‐band and G‐band, respectively. Measurement results show that from 110 GHz to 150 GHz and from 169 GHz to 193 GHz, the average insertion loss of the terahertz transition is around 0.54 dB and 0.89 dB, respectively. And their measured return losses are both larger than 10 dB. This work demonstrates that the investigated SIW to WR6/WR5 waveguide transitions can be used for developing future planar terahertz components by using the low cost PCB process.