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:
Nov. 29, 1994
Filed:
Jun. 28, 1993
Larry K Moreland, McHenry, IL (US);
Zenith Electronics Corp., Glenview, IL (US);
Abstract
A first mixer block converts received MMDS channel frequencies to MMDS frequencies capable of being processed by an MMDS decoder. The MMDS decoder, which includes a crystal controlled reference generator, is located in a benign environment. The reference is supplied to a phase locked loop for controlling a fixed frequency local oscillator that supplies the first mixer. The local oscillator output is also supplied to a second mixer that produces a response signal, of a different frequency, by biphase shift key modulation of said reference that is transmitted back to the transmitting site via the antenna. A squelch circuit precludes transmission of the unmodulated reference.