A tunable resonator enabled by a soft impedance surface

Abstract

We present a design for a cylindrical cavity resonator with a resonant frequency ( mode) that can be tuned by increasing the separation between the cavity's main body and a discrete lid. This is made possible by incorporating a soft impedance surface into the lid. Tuning between 5 and 6 GHz is achieved by increasing the lid‐to‐cavity separation from 0 to 1.5 mm. We will also discuss the field distribution within the cavity, and use it to explain how the cavity works, and limitations on the performance.