Patent ID: 6965284
Filing Date: 2005-11-15
Classification: H01P

Abstract:
1. A dielectric filter comprising: a dielectric substrate assembly including a first dielectric substrate, a second dielectric substrate on the first dielectric substrate, and a third dielectric substrate on the second dielectric substrate; a plurality of resonator electrodes made of metallic foil provided in the dielectric substrate assembly, each of the resonator electrodes having a first surface on the second dielectric substrate, a second surface opposite to the first surface, and a side surface connected to the first surface and the second surface, the resonator electrodes adapted to be electromagnetically coupled with each other; an inter-stage coupling capacitor electrode provided on the first dielectric substrate, the inter-stage coupling capacitor electrode for coupling the resonator electrodes; and an input/output coupling capacitor electrode provided on the third dielectric substrate, the input/output coupling electrode for inputting and outputting a signal to the resonator electrodes, wherein the dielectric substrate assembly has a first portion located on the first surface of each of the resonator electrodes, a second portion located on the second surface of each of the resonator electrodes, and a third portion located on the side surface of each of the resonator electrodes, and wherein a dielectric constant of the third portion of the substrate assembly is lower than one of a dielectric constant of the first portion of the substrate assembly and a dielectric constant of the second portion of the substrate assembly.