Patent ID: 6556108
Filing Date: 2003-04-29
Classification: H01P

Abstract:
A band-pass filter comprising:a dielectric substrate; at least one metallic film provided on a surface of the dielectric substrate or inside of the dielectric substrate; input-output coupling circuits connected to first and second portions of the periphery of the metallic film, wherein the shape of the metallic film and the positions of connection points of the input-output coupling circuits are such that a first resonance mode propagated substantially parallel to an imaginary straight line passing through the connection points of the input-output coupling circuits, and a second resonance include propagated substantially perpendicular to the imaginary straight line are generated; and a coupling mechanism arranged to make discontinuous at least a portion of a resonance current or a resonance electric field such that the first and second resonance modes are coupled to each other; wherein the shape of the metallic film is substantially triangular and the connection points of the input-output coupling circuits are located on adjacent sides of said substantially triangular metallic film.