Power amplifier module with stable idling current

A power amplifier module comprising:

• a bias circuit to produce an idling current;
• and
• a power amplifier of which gain is controlled by said idling current produced by said bias circuit,
• wherein said bias circuit further includes an ambient temperature detector to detect changes of ambient temperature so that effects of changes of ambient temperature of said power amplifier module can be removed by the ambient temperature detector without using Schottky diodes;
• wherein said bias circuit further includes a control voltage detector to detect changes of control voltage so that effects of changes of control voltage of said power amplifier module can be removed by the control voltage detector;
• wherein said bias circuit further comprises a differential circuit to make error amplification with said control voltage detector provided to perform as a standard voltage source for ambient-temperature detection of said ambient temperature detector and said ambient temperature detector provided to perform as a standard voltage source for control-voltage detection of said control voltage detector.

A power amplifier module comprising:

• a bias circuit for producing an idling current so that effects of changes of control voltage and ambient temperature can be removed;
• a power-amplifying transistor of which gain is controlled by the idling current produced by said bias circuit;
• a first matching circuit for feeding an input signal to the power-amplifying transistor;
• and
• a second matching circuit for feeding an output signal of the power amplifier circuit to a load circuit,
• wherein said bias circuit comprises:
• first means for detecting changes of control voltage of the module;
• a second means for detecting changes of ambient temperature of the module;
• and
• a differential circuit for making error amplification with the first means serving as a standard voltage source for ambient-temperature detection and the second means serving as a standard voltage source for control-voltage detection, and
• wherein said bias circuit, said power-amplifying transistor, and said first and second matching circuits are mounted on a printed circuit board.