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:
Dec. 31, 1985
Filed:
Dec. 27, 1982
Shunroku Sasaki, Yokohama, JP;
Kazuo Tsukada, Kakogawa, JP;
Yoshiharu Kanzaki, Sagamihara, JP;
Yoshikazu Hori, Yokohama, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A digital loop filter is used in a phase-tracking circuit which is adaptable to a phase-comparison radio navigation system such as the DECCA (registered trademark) system. The digital loop filter includes a feedback circuit which receives a digital input signal from the digital loop filter and outputs a digital output signal and which feeds back and adds the digital output signal to the digital input signal after a predetermined delay. It also includes a feed-forward circuit which multiplies the digital input signal by a predetermined constant (B) and adds the resultant signal to the digital output signal of the feedback circuit to generate a digital output signal. A multiplier for multiplying the digital output signal of the feed-forward circuit by a second predetermined constant (C) to generate a digital output signal of the digital loop filter is also provided.