A dielectric TEM mode resonator and a bandstop filter including such a resonator

摘要

A dielectric TEM mode resonator (20) comprisinga dielectric core (21) comprising first and second spaced apart faces (22, 23) and a side wall (24) extending therebetween, the first and second faces and side wall together defining an exterior surface (30);a conduit (27) extending through the dielectric core from an aperture (25) in the first face to an aperture (26) in the second face, the conduit wall defining an interior surface (29);an electrically conducting coating layer (31), the electrically conducting coating layer extending from the first aperture to at least partially coat the interior surface and at least partially coat the exterior surface, the coating not extending over the exterior surface as far as the second aperture;an electrically conducting rod (32) at least partially within the conduit; and,an electrically insulating layer (33) sandwiched between the rod and metal coating on the interior surface such that the rod is not in electrical contact with the electrically conducting coating.