Coupling radiation loss in the mirror dielectric disk resonator. Part 2. Mismatched waveguide coupling

The coupling radiation loss of the whispering gallery mode mirror dielectric disk resonator (MDDR) with mismatched waveguides was researched. The findings are of particular interest to the developers of MDDR solid-state oscillators where semi-conductor devices and impedance matching circuits are located in the waveguide, forming a complex load in the waveguide. The dependences of MDDR resonance frequency and Q-factor on the amplitude and phase of the wave reflected from inhomogeneities in the waveguide back to the resonator are measured. Two types of couplers (a hole in the diaphragm on the mirror and an open end of the narrower waveguide on the mirror) are studied. For the open end type coupler it has been shown that MDDR resonant frequency and Q-factor can be calculated using the proposed lumped elements scheme of MDDR coupler and measuring procedure described in the first part of this paper. Coupling radiation loss and Joule loss in the load which are brought in MDDR by the complex load in the waveguide are calculated.