A K-Band Reflective Waveguide Switch Using Liquid Metal

In this letter, a K-band reflective waveguide switch using eutectic gallium-indium, a liquid metal alloy, is presented. The switching mechanism for the proposed switch is based on inserting/removing metallic posts in the broad wall of the waveguide to consequently turn the switch off and on. One and two rows of metallic posts (three posts per row) are considered, and the performance of the switch for both cases is simulated and measured. It is demonstrated that insertion loss of as low as 0.1 dB (in the on state) and isolation of better than 30 dB (in the off state) are achieved at 20 GHz operating frequency. Wideband performance and power handling of the switch are also analyzed for the entire K-band (18-26 GHz), illustrating the potential of the proposed switch for wideband applications.