Abstract: A bias controller sets the quiescent current of a power amplifier to a desired value by dynamically adjusting the power amplifier bias voltage. Using closed-loop control, the bias controller sets the bias voltage to whatever value is needed despite circuit component variations and temperature effects. Operation of the bias controller complements dynamic bias voltage adjustment in advance of transmit operations, such as in advance of a transmit burst. In a first state, where the power amplifier is in a quiescent condition, the bias controller adjusts bias voltage to set the desired quiescent current by detecting the supply current into the power amplifier. The bias controller then transitions to a second state, where it maintains the adjusted bias voltage irrespective of amplifier supply current. Despite its ability to sense supply current into the power amplifier, the bias controller's configurations avoid dissipative current sensing during normal operation of the power amplifier.

Abstract: An apparatus and method for creating an amplifier input waveform based on received phase and amplitude information from an input signal. The apparatus includes a first switch receiving phase information from a primary waveform and a second switch in communication with the first switch and the input. The second switch receives amplitude information from the primary waveform and receives the phase information from the first switch and uses the amplitude information to modulate the phase information. A secondary waveform is thus created for input to the amplifier load matching network. In this way, an amplitude modulated waveform is amplified at high efficiency, enabling application of either all or part of the phase and/or amplitude modulation at the input of the amplifier.