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:
May. 14, 1985
Filed:
Nov. 05, 1981
Applicant:
Inventor:
Fumiaki Mukaiyama, Suwa, JP;
Assignee:
Kabushiki Kaisha Suwa Seikosha, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03D / ; H04L / ;
U.S. Cl.
CPC ...
329126 ; 329107 ; 329110 ; 375 45 ; 375 88 ; 375 94 ; 375 95 ; 375103 ;
Abstract
An FSK demodulation circuit especially suited for integrated construction is provided. The demodulating circuit uses N counters and a counter selector circuit for sequentially switching the counters at every zero-cross point in the received FSK signal. Sensitivity of demodulation is improved by N-time zero-cross detection rather than counting the time between two adjacent zero-cross points. The FSK demodulation circuit uses a Switched Capacitor Bandpass Filter whose characteristics are changed by changing the frequency of an internal clock using simple dividing circuitry.