The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 05, 1995
Filed:
Apr. 05, 1993
Alexander W Hietala, Cary, IL (US);
Troy L Stockstad, Phoenix, AZ (US);
Robert L Vyne, Tempe, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
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 temperature ranging from -55.degree. C. to +125.degree. C. and over power supply voltage ranging from 2.7 V to 4.75 V.