Dielectric resonator dual modes filter

In a shielded cylindrical dielectric resonator a number of degenerate modes with identical natural frequencies can be found. These degenerate modes can be coupled together to form coupled circuits by perturbating the geometrical configuration of the structure. The letter presents both TE01p mode resonant frequency perturbation by a tuning screw and a two modes dielectric filter using two perpendicularly polarised HE111 modes of the resonator.