Response of microwave dielectric-slab-loaded rectangular waveguide resonators to wall displacements

This paper presents the results of an investigation into the response of a microwave dielectric-slab-loaded waveguide resonator to displacements in its terminating wall. The resonator consists of a shorted microwave rectangular waveguide, loaded with a dielectric slab with one end of it tapered. It is shown that the resonant frequency of its hybrid longitudinal electric mode is ~10 times more sensitive to the wall displacement than the resonant frequency of a transverse mode of a half-wavelength resonator forming between the waveguide and the wall. The results can be used to construct efficient sensors for nondestructive evaluation of metal surfaces and for measurements of their displacements.