Microwave Notch Filters for Plasma Diagnostics, Numerical Simulation by Method of Moments with Mode Matching

A method of moments (MoM) with mode matching is proposed for numerical simulation of waveguide components including cavity resonators. Waveguide Ka-band notch filters with cavity resonators were simulated by the proposed method and manufactured; their simulated and measured characteristics were in a good agreement. Using proposed method the notch filter with pyramidal shape resonator was simulated and designed. Attenuation of 52 dB was achieved at notch frequency of 240 GHz, which makes the filter to be promising in plasma diagnostics systems in a prototype of an industrial fusion reactor of the next generation (DEMO).