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:
Oct. 09, 2001
Filed:
Nov. 29, 1999
Shigeki Takeda, Kyoto, JP;
Kyocera Corporation, Kyoto, JP;
Abstract
A distributed element filter is realized which has bandpass characteristics realizing both a flat amplitude characteristic and a flat group delay characteristic throughout the passband at the same time, while realizing transmission zeros in the stopbands. The transfer function s21 of a lowpass prototype filter is expressed by a numerator rational polynomial f(s) having at least one conjugate zeros on the real axis and one conjugate zeros on the imaginary axis and a denominator rational polynomial g(s) as a Hurwitz polynomial of degree 6 or higher; circuit blocks corresponding to the zeros on the real axis and zeros on the imaginary axis are each realized by a multiple resonator filter, and the distributed element filter is realized by a multiple coupling circuit block by setting the conditions on each coupling in corresponding relationship to the zeros on the real axis or zeros on the imaginary axis. The filter having the desired bandpass characteristics can thus be constructed and realized with simple circuitry by using a strict design procedure.