| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus capable of optimizing power efficiency of a power amplifier using a small-scaled circuit. SOLUTION: A bias voltage control section 2 calculates an output power of a PA 8 based on a TPC signal and determines a bias voltage to be applied to bias tees 7-1, 7-2 for maximizing power efficiency of the PA 8. The bias voltage control section instructs Duty variation circuits 5-1, 5-2, varies a duty of frequency dividing signals of transmission frequency signals generated by frequency divider circuits 6-1, 6-2 and gives the signals to DC/DC converters 4-1, 4-2 as driving signals. The DC/DC converters 4-1, 4-2 transform a voltage of a power source 3 to the relevant voltage according to the driving signals and apply the voltage to the bias tees 7-1, 7-2. Thus, output power of the PA 8 is controlled. COPYRIGHT: (C)2006,JPO&NCIPI |
