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. 20, 1976
Filed:
Oct. 04, 1973
Nobuaki Takahashi, Yamato, JA;
Yoshiki Iwasaki, Yokohama, JA;
Masao Kasuga, Sagamihara, JA;
Yasuo Itoh, Tokyo, JA;
Victor Company of Japan, Limited, Yokohama, JA;
Abstract
A system for demodulating angle modulated waves comprises a phase locked loop including a phase comparator and a voltage controlled oscillator. An attenuation means is inserted into the phase locked loop. This attenuation means does not affect the DC component of an input angle modulated wave, but does cause an attenuation with respect to an AC component, to cause a decrease in the loop gain. The phase locked loop has a DC lock range exhibiting a relatively wide lock range width even when the input level is relatively low and an AC lock range produced by the attenuation circuit and exhibiting a relatively narrow lock range width when the input level is relatively low. The attenuation means detects an abnormality in the angle modulated wave, the harmonics component of the direct wave, and the like. A variable attenuation circuit controlled by the output of the detecting means is varied in its attenuation quantity.