Dual-mode band-pass filter

摘要

In a dual-mode bandpass filter, a metal film is partially formed on one surface of a dielectric substrate or at a certain vertical level within the dielectric substrate, first and second input/output coupling circuits are coupled to the metal film, at least one capacitor is loaded to the metal film so that when an input signal is applied from either input/output coupling circuit, two resonant modes generated in the metal film are coupled. The capacitor preferably includes via-hole electrodes opposing the metal film.