Waveguide variable attenuator suitable for electromechanical control

The paper continues research of microwave devices consisting of rectangular waveguide section with dielectric slab in it. The air clearance exists between dielectric slab and wide wall of the waveguide. Variation of the clearance by means of external actuator influences on propagation constant of the wave travelling through the device. This way the device can produce variable phase shift. Under certain conditions waveguide section goes beyond cutoff, and variable clearance produces controllable attenuation. Combined with high speed actuator device can operate as fast tunable attenuator or switch. The paper presents electromagnetic field problem and simulation results.