HIGH FREQUENCY POWER AMPLIFIER CIRCUIT AND RADIO COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a high frequency power amplifier circuit and a radio communication system in which output power can be controlled by a power supply voltage and a change in the output power is reduced even when the power supply voltage changes even when the battery voltage or the temperature changes.

SOLUTION: The high frequency power amplifier circuit (RF power module) is constituted such that the input bias voltage of the transistor (Q13) for amplification in the final stage of the high frequency power amplifier circuit (210) is supplied by a transistor (Q23) current-mirror-connected with the transistor for the amplification in the final stage and a transistor (TR1) for power supply voltage control for controlling the power supply voltage to be applied to the transistor for the amplification in the final stage at least on the basis of an output control voltage is provided on the power supply voltage terminal side of the transistor for the amplification. The high frequency power amplifier circuit is provided with a transistor (TR2) for current detection for forming a current mirror with the transistor for the power supply voltage control and making a current proportional to the current flowing to the transistor for the power supply voltage control flow and a current/voltage conversion means (Rs) for converting the current flowing to the transistor for the current detection to a voltage.

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