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:
Oct. 20, 1992
Filed:
Aug. 10, 1990
Applicant:
Inventors:
Ian G Fobbester, Fairford, GB;
David S Clarke, Blunsdon, GB;
Assignee:
Plessey Overseas Limited, , GB;
Primary Examiner:
Int. Cl.
CPC ...
H03D / ; H03K / ;
U.S. Cl.
CPC ...
328133 ; 328155 ; 328151 ; 307262 ; 307516 ; 307514 ; 331 / ; 331 18 ;
Abstract
A phase detector for a phase locked loop frequency synthesizer, in which frequency-divided signals from a variable frequency oscillator and a reference oscillator are used to trigger respective ramp waveform generators, and a sample pulse generator is arranged to be responsive to the reference ramp waveform to provide sample pulses centered at the mid-point of that ramp waveform to respective sample and hold circuits, the relative phases of the ramp waveforms being determined from the sampled and held voltages.