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:
Feb. 19, 1985
Filed:
Jul. 05, 1983
Charles W Shanley, Plantation, FL (US);
William V Braun, Pompano Beach, FL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A radio frequency transceiver is provided in which the crystal resonator and monolithic crystal filter devices therein all operate at or near the operating frequency of the transceiver, and which employs a single piezoelectric element to achieve the functions of receiver signal filtering, transmitter signal filtering, receiver local oscillator signal generation, and transmitter local oscillator signal generation. To achieve these functions, a crystal resonator and a monolithic crystal filter are situated on the same substrate of piezoelectric material. The crystal resonator portion of the piezoelectric device is employed to control the frequency at which a local oscillator generates radio frequency energy. Such crystal controlled local oscillator is shared by a receiver mixer circuit and a transmitter mixer circuit. Switching circuitry is employed to switch the crystal filter portion of the piezoelectric device from the receiver signal path to the transmitter signal path.