Control circuit for mobile telephone with full duplex operation capability
US4811390A · kind A · utility
6Cited by
1References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1987 |
| Grant date | Mar 7, 1989 |
| Priority date | — |
| Expiry date | Jul 16, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A circuit which is used with a portable or mobile telephone system. The circuit is arranged to be installed between the telephone control unit and the radio transceiver used in mobile telephone systems. The circuit permits "normal" telephone usage with the telephone handset, as well as "hands-free" or speaker-phone operation. Also, duplex (i.e. bidirectional) operation is achieved by reducing, but not eliminating, two-way signal transmission through the circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.