High frequency power amplifying module and wireless communication apparatus

摘要

A high frequency power amplifier module is provided for improving output controllability. A wireless communication apparatus incorporates a high frequency power amplifier module in a multi-stage configuration including a plurality of cascaded MOSFETS. The power amplifier module comprises a bias circuit for generating a gate voltage in response to a power control voltage (vapc) generated based on a power control signal of the wireless communication apparatus. The gate voltage has a bias pattern which presents smaller fluctuations in output power in response to a control voltage (Vapc) in a region near a threshold voltage (Vth) of the MOSFETs in respective amplification stages. In this way, the controllability for the output power is improved. More specifically, the power amplifier module has a gate bias circuit for generating the gate voltage (Vg) which follows a gate voltage pattern. The gate voltage (Vg) supplied to a control terminal in response to the control voltage (Vapc) largely changes in a region where the gate voltage (Vg) is lower than the threshold voltage (Vth) of the respective MOSFETs, and slightly changes near the threshold voltage (Vth). Also, the gate voltage (Vg) presents desired characteristics from the vicinity of the threshold voltage (Vth) to a high Vapc voltage region.