Technology Development of a High Power Low-Cost Waveguide Switch for Satellite Transponder Applications

This article presents a double pole double throw (DPDT) waveguide switch in the Ku band with significantly lower manufacturing costs than competing switches. The switch structure consists of a fixed ring and a rotating cylinder at its center, separated by an unavoidable narrow air gap. An electromagnetic band gap (EBG) structure minimises leakage in this gap. Gap waveguide technology effectively mitigates leakage waves by incorporating a perfect magnetic conductor (PMC), restricting wave propagation within a specific frequency range. For cost-effective implementation of the EBG region, a glide-symmetric holey structure (GSHS) is proposed. This structure consists of two parallel perforated conductor plates with a narrow air gap, where the holes are arranged alternately in a triangular grid. In the proposed switch, the holes in the inner cylinder are offset from those in the outer ring by half a period, minimizing leakage effectively. Design and simulation results demonstrate that the switch achieves a transmission loss of 0.05 dB and a return loss of less than −35 dB at its ports. Additionally, the port isolation exceeds 80 dB, and the switch offers a relative bandwidth of more than 50%, outperforming similar designs.