Magnetic modes in a resonator built around a circular evanescent waveguide and coaxial line

The eigenfrequencies of magnetic modes in a resonator made up of two segments of a circular evanescent waveguide and a coaxial line are found by solving an electrodynamic problem. For the fundamental H_11dH_{11\delta } mode, the performance of the resonator is studied analytically and experimentally over a wide range of its parameters. The feasibility of a high-power microwave semiconductor oscillator based on the resonator under study is demonstrated.