Laminated dielectric filter, and antenna duplexer and communication equipment using the same

摘要

A laminated dielectric filter is formed by coupling a plurality of resonators to one another by electromagnetic-field coupling. In the laminated dielectric filter, a bypass circuit formed of a series circuit including bypass capacitors and transmission lines is provided in parallel to a magnetic-field bypass coupling between non-adjacent resonators. Thus, capacitance of the bypass capacitors can be regulated without being affected by the magnetic-field bypass coupling between the non-adjacent resonators. As a result, attenuation poles outside a passband can be controlled freely.