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. 24, 1989
Filed:
Jun. 29, 1987
Shigeo Yoshizawa, Tokyo, JP;
Eiichi Ishii, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An FM demodulator having improved demodulation sensitivity, and suitable for monolithic integration. As demonstrated in various embodiments, increased sensitivity is made possible= by narrowing the demodulation band on a low frequency side. According to the various embodiments, a monostable multivibrator or first pulse generator receives an input signal and provides an output having first and second states having a combined duration equal to one period of the input signal, or alternatively equal to one-half period of the input signal. A second pulse generator, responsive to the output of the first pulse generator, generates another output having third and fourth states whose combined duration is the same as the combined duration of the first and second states. Demodulation is accomplished finally through a low-pass filter, which integrates the output of the second pulse generator.