Antenna switching apparatus for selectively connecting antenna to transmitter or receiver
US5442812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1994 |
| Grant date | Aug 15, 1995 |
| Priority date | — |
| Expiry date | Sep 16, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01P1/15
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An antenna switching apparatus for selectively connecting an antenna to either a transmitter for transmitting a transmitting signal having a transmitting frequency, or a receiver for receiving a receiving signal having a receiving frequency, which is different from the transmitting frequency, includes an antenna terminal electrically connected to the antenna; a transmitting terminal electrically connected to the transmitter, and a receiving terminal electrically connected to the receiver. A receiving filter for passing a receiving signal therethrough is electrically connected between the antenna terminal and the receiving terminal. An impedance adjusting element is electrically connected to an input end of the receiving filter, and has an element value such that an impedance when seen from the antenna terminal looking toward the receiving filter becomes substantially infinity at the transmitting frequency. Further, a switching device is electrically connected between the antenna terminal and the transmitting terminal, wherein it is turned on or off in response to a control signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.