Simplex transceiver employing a common piezoelectric element for transmitting and receiving
US4501018A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 5, 1983 |
| Grant date | Feb 19, 1985 |
| Priority date | — |
| Expiry date | Jul 5, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/44
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.