Temperature-coefficient controlled radio frequency signal detecting circuitry
US5448770A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1993 |
| Grant date | Sep 5, 1995 |
| Priority date | — |
| Expiry date | Apr 5, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D1/18
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A TC controlled RF signal detecting circuitry (211) used in the output power control circuit of a TDMA RF signal power amplifier includes positive coefficient current source (303) producing current I+ having a positive TC, negative coefficient current source (305) producing current I- having a negative TC, and current mirror (301) for summing currents I+ and I- to produce substantially identical compensated mirror currents Im1 and Im2. Anti-clamping current mirror (309) mirrors current Im2 to produce compensated currents Ia1 and Ia2, which are applied to and bias a Schottky diode coupled in series to a resistor network in each leg of diode detector (311). Each leg of diode detector (311) has a positive TC, which is substantially offset by the negative TC of compensated currents Ia1 and Ia2. Schottky diode (431) in one leg of diode detector (311) half-wave rectifies RF feedback signal (212) to produce temperature and voltage compensated power level signal (229), which has a DC level proportional to the output power level of RF output signal (214). By using TC controlled RF signal detecting circuitry (211), power level signal (229) has a DC level which is stable to within 5 mV over t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.