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:
Nov. 25, 1980
Filed:
Feb. 02, 1979
Kazuo Watanabe, Kokubunji, JP;
Masanori Ienaka, Kodaira, JP;
Yasuo Kominami, Kokubunji, JP;
Makoto Homma, Tokyo, JP;
Hitachi, Ltd., , JP;
Abstract
An FM detector is constructed of a phase shift network and an analog multiplier. The analog multiplier includes a differential amplifier circuit and a phase detector circuit. The differential amplifier circuit includes differential pair transistors which are driven by FM intermediate frequency signals. A base emitter junction of a diode-connected transistor is connected across a base and an emitter of one of the differential pair transistors. The base of the one transistor and a base of the diode-connected transistor are connected to an emitter of an emitter-follower transistor, and the FM intermediate frequency signal is applied to a base of the emitter-follower transistor. Noise which develops in the base of the differential pair transistor or the base of the diode-connected transistor is reduced by the low output impedance of the emitter-follower transistor, so that the signal-to-noise ratio of the FM detector is improved.