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:
Nov. 19, 2002
Filed:
Oct. 28, 1999
Abstract
The present invention provides a dielectric filter capable of increasing a designing freedom for obtaining a desired filter characteristic and capable of producing an attenuation pole in the vicinity of passing frequency band, also to provide a duplexer and communication apparatus formed by using the dielectric filter and the duplexer. In a dielectric block there are formed two through holes of rectangular cross section extending from a first end face to a predetermined depth, with the internal sizes thereof being different from each other. In this way, it is possible to enlarge the ranges obtainable by mutual capacitances on an open face side and a short circuit face side, thereby making it sure to dispose an attenuation pole in the vicinity of a passing frequency band.