Patent attributes
An RF power amplifier includes a push-pull amplifier having field effect transistors. Temperature compensating bias circuitry provides a temperature compensated bias voltage to the transistors for decreasing the bias voltage thereof as temperature increases. The temperature compensating bias circuitry includes a temperature sensor generating a temperature signal. A first amplifier provides a first temperature dependent voltage based on the temperature signal. A second amplifier provides a second temperature dependent voltage based on the temperature signal. The first and second temperature dependent voltages change at substantially the same rate in response to the temperature signal. A potentiometer receives the first and second temperature dependent voltages such that a voltage across the potentiometer remains substantially constant when the first and second temperature dependent voltages change. An output of the bias circuitry is connected to at least one of the transistors and supplies the temperature compensated bias voltage to the at least one of the transistors.
