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:
Mar. 13, 1979
Filed:
Feb. 21, 1978
Kazuya Togawa, Hakui, JP;
Kimio Masaie, Hakui, JP;
Murata Manufacturing Co., Ltd., Nagaokakyo, JP;
Abstract
An improved quadrature detector for producing a frequency demodulated signal employing a low reactance phase shifter. A quadrature FM detector demodulates a frequency modulated signal by phase comparison of a signal directly from the limiter with a signal coupled through a multi-mode resonator tank circuit and a 90.degree. phase shift circuit. In the prior art the 90.degree. phase shift circuit includes a series coupled capacitor having a high reactance which tends to attenuate the signal and decrease the low distortion bandwidth. Accordingly in the present invention a coil is connected across the input or output terminals of the multi-mode tank circuit thereby enabling the phase shift circuit to employ a low reactance capacitor yielding an improved signal level and low distortion bandwidth.