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:
Jun. 16, 1981
Filed:
Nov. 28, 1979
Applicant:
Inventor:
Hitoshi Hirata, Tokyo, JP;
Assignee:
Pioneer Electronic Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H04H / ;
U.S. Cl.
CPC ...
179 / ; 455260 ;
Abstract
A quadrature receiver circuit in which the output frequency of a local oscillator is controlled to follow the free-running frequency of a voltage-controlled oscillator so that accurate four-phase demodulation is maintained independent of oscillator drift. The output control voltage of a phase comparator in a phase-locked loop circuit in the demodulator is coupled through a low-pass filter and a DC amplifier to the frequency control input of a voltage controlled local oscillator.