General Resonance Condition for Waveguide Junctions with Natural Dielectric Inserts

A general resonant condition for rectangular waveguide junctions operating in the single mode regime of the main waveguide is formulated based on previously developed mathematical models. We will consider three types of junction with various side arms: semi-infinite waveguide oriented in line with main waveguide, T-oriented semi-infinite waveguide with an impedance end wall, and infinite perpendicularly oriented waveguide. The main waveguide is coupling with the side arm through a narrow slot, and it has a dielectric insert in the coupling region. The simulation results obtained for the waveguide junctions have shown that the resonant conditions allow to attain correct results without taking into account the imaginary part of permittivity of the insert material.