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, 1978
Filed:
Aug. 09, 1976
Yukinobu Ishigaki, Yamato, JA;
Kohei Sasamura, Sagamihara, JA;
Victor Company of Japan, Ltd., Yokohama, JA;
Abstract
The inventive system demodulates angle-modulated signals. A tracking band-pass filter responds to an input angle-modulated wave signal. The tracking filter has a pass band with a center frequency controlled by a control signal. A first amplitude limiter limits the amplitude of the input angle-modulated wave signal. A differentiation circuit establishes a 90.degree. phase difference between a signal passing through the tracking band-pass filter and a signal passing through the amplitude limiter. A phase comparator responds to an input with the two signals with a 90.degree. phase difference therebetween and produces an output error signal in accordance with this phase difference. This output error signal is supplied as the control signal to the tracking band-pass filter. This output error signal is also passed through a low pass filter to obtain the demodulated signal.