Modeling and Measurements of the Parameters of a Quasi-optical mm-Wave Resonator by Means of a Tunable Grid Coupler

The results of modeling and measurements of the performance parameters of new configuration of the tunable 3-grids coupler combined with a quasi-optical mm-wave resonator are presented. By means of grid rotation and grid assembly shift, it is possible to control the output power of a Free Electron Maser (FEM) and tune its oscillation frequency accurately. The coupler was used to evaluate the quality parameters of the resonator by measuring the reflection coefficient Sl1(f) of the resonator through the coupler. There is good agreement between theory and experiment.