Single-Pole Single-Throw Switch for Substrate-Integrated Waveguide

A novel concept of a simple single-pole single-throw switch implementation for a substrate-integrated waveguide is presented in this letter. The switch design is an adaptation from the antenna theory where a resonant slot on a rectangular waveguide, inclined with respect to the line axis, realizes a series impedance load on the waveguide. This impedance can be designed to attenuate the signal flowing through the transmission line while minimizing radiation and can be activated by loading the slot with a diode. A prototype was fabricated to validate the proposed concept. The prototype was measured and it had an ON-state insertion loss of less than 1.3 dB, an OFF-state isolation of more than 10 dB, and a switchable bandwidth of 21% at 22 GHz.