Patent ID: 7366481
Filing Date: 2008-04-29
Classification: H03F,H03G,H04L

Abstract:
1. A radio communication apparatus comprising: a base band unit which generates signals to be transmitted; a modulator which modulates the signals; a phase detector which detects a phase component of the signals modulated by the modulator; an amplitude detector which detects an amplitude component of the signal modulated by said modulator; an oscillator which generates a transmission signal in accordance with an output of the phase detector; a power amplifier which amplifies the transmission signal; a feedback path which supplies an output level instruction signal of the power amplifier circuit to the amplitude detector; and a forward path which supplies an output of the amplitude detector to the power amplifier for control of an amplitude of the transmission signal; wherein the forward path includes a loop filter which generates a voltage in response to the output of the amplitude detector; a first amplifier which amplifies the voltage; a charge pump circuit which includes a capacitor, a current source for charging said capacitor, a current sink for discharging a charge on said capacitor, and which is configured to operate the current source and the current sink in response to an output of the first amplifier to accumulate a charge on the capacitor; and a precharge unit which is arranged between the first amplifier and the power amplifier and which is capable of rapidly increasing a control voltage by charging the capacitor for the power amplifier to a power threshold on starting transmission.