The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 10, 2002
Filed:
Jul. 10, 2000
Abstract
A laminated filter comprising a plurality of resonator electrodes, an inter-resonator coupling capacitor electrode for coupling adjacent resonators, and two input/output coupling capacitor electrodes for coupling input/output terminals and the resonator electrodes. This provides a capacitor electrode for electrically connecting one side of the input/output terminals with a portion of the input/output coupling capacitor electrode, wherein the input/output coupling capacitor electrode and the capacitor electrode are a parallel circuit. This structure forms a parallel resonance circuit in the input/output terminal, to provide an additional attenuation pole besides an attenuation pole formed by electromagnetic coupling between the resonators and an inter-resonator capacitance, thereby realizing a laminated filter of a high attenuation. With this structure, a duplexer can be made using a plurality of the filters of this invention without requiring a phase-shifting circuit.