Abstract: In a portable radio transceiver, a power amplifier system includes a saturation detector that detects power amplifier saturation in response to duty cycle of the amplifier transistor collector voltage waveform. The saturation detection output signal can be used by a power control circuit to back off or reduce the amplification level of the power amplifier to avoid power amplifier control loop saturation.

Abstract: In a portable radio transceiver, a power amplifier system includes a saturation detector that detects power amplifier saturation in response to duty cycle of the amplifier transistor collector voltage waveform. The saturation detection output signal can be used by a power control circuit to back off or reduce the amplification level of the power amplifier to avoid power amplifier control loop saturation.

Abstract: In a portable radio transceiver, a power amplifier system includes a saturation detector that detects power amplifier saturation in response to duty cycle of the amplifier transistor collector voltage waveform. The saturation detection output signal can be used by a power control circuit to back off or reduce the amplification level of the power amplifier to avoid power amplifier control loop saturation.

Abstract: The invention provides a system that enables a power amplifier to operate in a compressed mode and then be switched during operations to operate in a linear mode. Broadly conceptualized, the system may include a power amplifier and a bias controller that efficiently permits a communication device to function with either the compressed waveforms of a first air interface system or linear waveforms from other air interface systems.

Abstract: The invention provides a system that enables a power amplifier to operate in a compressed mode and then be switched during operations to operate in a linear mode. Broadly conceptualized, the system may include a power amplifier and a bias controller that efficiently permits a communication device to function with either the compressed waveforms of a first air interface system or linear waveforms from other air interface systems.

Abstract: The invention includes an amplifier and a biasing circuit. The amplifier may have one or more driver stages and a final stage. Each stage may be connected in series to pass along and amplify an input signal from one stage to the next. The input signal level may increase over time. The biasing circuit may include a voltage follower having an output and a reference transistor. Each stage may include a transistor having a base that is connected to the output of the voltage follower. A resistor may be placed between each transistor stage base and the output of the voltage follower. The base of the final stage transistor may be DC connected to the reference transistor base. In operation, the reference transistor collector current and thus the final stage base bias voltage may be maintained at fixed level by feedback through the voltage follower.