Patent ID: 7450921
Filing Date: 2008-11-11
Classification: H03B,H03L,H04B

Abstract:
1. A mobile communication device such as a mobile telephone, comprising: an antenna; an antenna switch which couples the antenna and switches a transmission signal and a reception signal; a communication semiconductor integrated circuit which couples the antenna switch and which demodulates the reception signal and modulates the transmission signal; a power amplifier which couples between the antenna switch and the communication semiconductor integrated circuit device and which amplifies a signal to be transmit from the communication semiconductor integrated circuit device and outputs the transmission signal, wherein the communication semiconductor integrated circuit device comprises: a phase control loop, including: a transmission oscillator which receives a control voltage for determine a oscillation frequency of the transmission oscillator and outputs a phase modulated signal, a phase comparator which compares a phase of an output signal from the transmission oscillator and a phase of a phase and amplitude modulated signal; and a charge pump which generates the control voltage according to an output of the phase comparator, and an amplitude control loop, including an amplitude comparator which compares an amplitude of the transmission signal and an amplitude of a phase and amplitude modulated signal (TXIF) and which generates a voltage according to an amplitude difference and outputs the voltage to the power amplifier as an output level control signal, wherein a variation of the control voltage versus oscillation frequency characteristic of the transmission oscillator is corrected by calibrating a current of the charge pump.