Sub-THz Photoconductive Evanescent-Mode Waveguide SPST Switch

This letter presents the first measured results of sub-THz photoconductive evanescent-mode (EVA) waveguide single-pole single-throw (SPST) switches operating in the G-band. Both second- and third-order devices are designed, fabricated, and measured, resulting in low insertion losses (ILs) of <0.4 dB and electronically tunable isolation reaching >50 dB while requiring low optical powers. An analysis of the solid-state plasma (SSP) physics reveals the viable potential for switching at frequencies above 800 GHz, emphasizing the promising capabilities of this enabling platform technology for future 5G/6G communication and radar sub-THz applications.