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:
Sep. 05, 2000
Filed:
Mar. 05, 1998
Applicant:
Inventors:
Trevor P Beatson, Manchester, GB;
Nicholas Mihailovits, Sale, GB;
Brendan P Fenney, Prestwich, GB;
David I Boddy, Rawtenstall, GB;
Assignee:
Mitel Semiconductor Limited, Wiltshire, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
327553 ; 327557 ; 330305 ;
Abstract
A frequency tracking arrangement in which a frequency tracking circuit utilizes a continuously variable analogue first order all-pass filter circuit as a controllable phase-shift element in a closed-loop system which produces a control signal to control the phase shift circuit to introduce a 90.degree. phase shift of a received reference frequency signal when the circuit is tracking that reference frequency. The control signal may then be utilized to slave the cut-off frequency of a filter and/or the delay time introduced by a delay line.