Filter utilizing combination of TE and modified HE mode dielectric resonators

A dielectric resonator filter comprising a metal wall (11) that is configured with metal cavities. Dielectric resonators (12, 14, 15) and (16) can be placed in the metal cavities and configured as a set of cylindrical TE mode resonators (12) and (14) and a set of rectangular HE mode resonators (15) and (16). Separating walls (13) are disposed between the dielectric resonators (12, 14, 15) and (16), which include tunable irises (17) for electromagnetic mixed coupling between the cylindrical TE mode resonators (12) and (14) and the rectangular HE mode resonators (15) and (16). The rectangular HE mode resonators (15) and (16) are configured to push far up the TE mode in frequency. This leads to an easy separation of two degenerate HE modes, a wide spurious free stop band and also achieves electric coupling without using any additional coupling member.