| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce drops in power-added efficiency (PAE) at low power and middle power modes of an RF power amplification circuit including multiple amplification stages. <P>SOLUTION: An RF power amplification circuit 313 includes an upstream amplifier 310, a downstream amplifier 311 and a control section 312. The upstream amplifier 310 responds to an RF transmission input signal Pin, and the downstream amplifier 311 responds to an amplified signal output from the upstream amplifier 310. In response to an output power control voltage Vapc, the control section 312 controls idling currents of the upstream amplifier 310 and downstream amplifier 311 to control gains of the upstream amplifier 310 and downstream amplifier 311. In response to the output power control voltage Vapc, the idling current and gain of the upstream amplifier 310 continuously change according to a first continuous function 2ndAmp, and the idling current and gain of the downstream amplifier 311 continuously change according to a second continuous function 3rdAmp. The second continuous function 3rdAmp is a function higher than the first continuous function 2ndAmp by one or more orders. <P>COPYRIGHT: (C)2013,JPO&INPIT |
