FILTER, BRANCHING FILTER, WIRELESS COMMUNICATION MODULE, BASE STATION, AND CONTROL METHOD

摘要

The objective of the invention is to provide a profile-reduced or size-reduced filter. A filter comprises: a metallic casing; an opening that is formed in the metallic casing; a metallic cover that covers the opening; and transverse magnetic (TM) mode dielectric resonators that are disposed in the opening and that are in electrical contact with the bottom surface of the metallic casing and with the metallic cover, said filter being configured such that the heights of the TM mode dielectric resonators are lower than the lowest of the heights of one-quarter wavelength semi-coaxial resonators that could be disposed in the opening.