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:
Jan. 03, 1995
Filed:
Jul. 15, 1993
Applicant:
Inventors:
Youhei Ishikawa, Nagaokakyo, JP;
Seiji Hidaka, Nagaokakyo, JP;
Assignee:
Murata Manufacturing Co., Ltd., Kyoto, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03H / ; H01P / ; H01P / ;
U.S. Cl.
CPC ...
333175 ; 333202 ; 3332191 ; 330109 ;
Abstract
An active-type band pass filter achieves a compact structure and a minimum noise figure by setting a coupling Q factor (Q.sub.e1) on an input side of an amplifier, a coupling Q factor (Q.sub.e2) on an output side of the amplifier, and a gain G of the amplifier so that they satisfy the condition that Q.sub.e1 <Q.sub.e2 and 1/Q.sub.e1 =G/Q.sub.e2. By increasing the term with the negative symbol in the equation ##EQU1## the total no-load Q factor (Q.sub.o) is set in the negative region.