Power control circuitry for a TDMA radio frequency transmitter
US5193223A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1992 |
| Grant date | Mar 9, 1993 |
| Priority date | — |
| Expiry date | Jul 27, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/56
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A TDMA cellular telephone (600) includes in its transmit signal path, microphone (608), vocoder (612), data format circuitry (601), quadrature modulator (602), 90 MHz local oscillator (606), transmitter with mixer (604), transmitter filter (618), and antenna (620). In its receive signal path, the TDMA cellular telephone (600) includes receiver filter (622) coupled to antenna (620), quadrature demodulator (624), and data deformat circuitry (625). The channel frequency of TDMA cellular telephone (600) is loaded into synthesizer (616) by microcomputer (614) and applied to transmitter (604) and demodulator (624). TDMA cellular telephone (600) is controlled by microcomputer (614) which includes a memory with a control and signaling computer program stored therein. Transmitter (604) includes novel power control circuitry (100) comprised of variable gain stage (104), mixer (106), bandpass filter (109), and directional coupler (112) in a forward path, and detector (116), A/D converter (118 ), digital controller (120), and D/A converter (126) in a feedback path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.