Microwave Resonators

Abstract

This chapter examines various resonator configurations highlighting their main applications and limitations. It addresses the one-port measurement, where reflection-type measurements are taken at an input port, coupled capacitively or inductively to the resonator. The chapter provides an overview of the theoretical and experimental techniques for evaluating the resonant frequency and unloaded Q factor of microwave resonators. An accurate calculation of the unloaded Q factor of microwave resonators requires knowledge of the conductivity of the metal walls as well as the dielectric loss tangent for resonators that are loaded with dielectric materials. The use of the transverse resonance technique for the evaluation of the resonant frequency of transmission-line resonators is described by considering a microstrip resonator loaded with a capacitive discontinuity. The chapter illustrates two approaches for calculating the resonant frequency of arbitrarily shaped resonators: the eigenmode analysis and the s-parameter analysis.