POWER AMPLIFIER MODULE

PURPOSE: A high frequency power amplifier is provided to improve the efficiency by outputting a different voltage according to a mode in a DC(Direct Current)-DC converter. CONSTITUTION: A mobile station modem(110) detects the strength of a signal received from a base station to output a control signal corresponding to the strength and changes a power mode according to the strength. A radio frequency transmitter(120) outputs an RF(Radio Frequency) signal for varying an RF signal level by the control signal outputted to the mobile station modem(110). A driver amplifier(130) is operated by a base current and an operation voltage(Vcc) applied from outside and amplifies firstly the RF signal inputted through the radio frequency transmitter(120). A power amplifier(140) is operated by the base current and the operation voltage(Vcc) to amplify secondly the RF signal applied through the driver amplifier(130). A base bias circuit(150) supplies a constant base current to the driver amplifier(130) and the power amplifier(140) by using a reference voltage(Vref). A DC-DC converter(160) supplies different operation voltages(Vcc) to the driver amplifier(130) and the power amplifier(140) according to an output signal of the mobile station modem(110). An input match(170) is installed between the radio frequency transmitter(120) and the driver amplifier(130) to transfer maximum power to driver amplifier. An interstage match(180) is installed between the driver amplifier(130) and the power amplifier(140) so that a maximum power is transferred from the driver amplifier(130) to the power amplifier(140). An output match(190) is installed on an output terminal of the power amplifier(140) so as to have a maximum output of the RF signal outputted from the power amplifier(140). 본 발명은 고주파 전력 증폭기에 관한 것으로, 더욱 상세하게는 고주파 전력 증폭기 내에 복수의 서로 다른 전압을 출력하는 DC-DC 컨버터를 설치하고, 하이 파워 모드와 로우 파워 모드에 따라 DC-DC 컨버터로부터 출력되는 전압(Vcc)의 레벨을 제어하여 DC-DC 컨버터에서 모드에 따라 각기 다른 전압이 출력되도록 함으로써 로우 파워 모드시 고주파 전력 증폭기의 소모 전류를 상대적으로 많이 줄여 고주파 전력 증폭기의 효율을 개선시킬 수 있다.