High frequency power amplifier module
AssigneeRenesas Technology Corp.
InventorsMasami Ohnishi, Hitoshi Akamine
Life of this patent
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Abstract
The present invention provides a power amplifier module used in a cellular phone or the like. In the power amplifier module, a bias control circuit converts a bias voltage to a current by MOS transistors, whereby a voltage drop is reduced and the value of the bias voltage is lowered. Bias control signals outputted from the bias control circuit are inputted to a high-frequency amplifying unit through low-pass filters. The low-pass filter comprises an inductance, and a condenser. Each of the condensers attenuates an envelope frequency. Each of the inductances suppresses a change in impedance at a carrier frequency of a modulation signal.
Claims10
A high frequency power amplifier module, comprising:
- a transistor which performs current amplification, based on a bias control signal inputted to a base terminal thereof;
- a first bias control circuit which generates the bias control signal;
- a low-pass filter connected between an output portion of the first bias control circuit and the base terminal of the transistor;
- and
- a reference voltage generating unit which generates a reference voltage from a converted current,
- wherein the first bias control circuit includes:
- a current conversion unit which converts a bias voltage into a current to thereby generate the converted current;
- and a buffer which effects buffering on the reference voltage generated by the reference voltage generating unit.
Dependencies are inferred from the claim text.