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. 05, 1999
Filed:
Dec. 06, 1996
John E Foster, Huntington, NY (US);
Pittway Corp., Chicago, IL (US);
Abstract
A method and apparatus for testing a balanced diode mixer and local oscillator combination in a microwave receiver. The diodes comprising a balanced mixer are unbalanced in a selective, controlled manner to generate an offset signal. The unbalancing of the mixer is accomplished by heating one of a pair of mixer diodes. By measuring an offset voltage output of the balanced diode mixer after one of the diodes has been heated, it is possible to measure an artificially created diode mismatch offset voltage and thereby verify that the balanced mixer/oscillator combination is working properly. The heating step is performed by either forward biasing the mixer diode or by placing a resistive heating element adjacent to the diode.