Patent ID: 6819180
Filing Date: 2004-11-16
Classification: H03F,H03G

Abstract:
An adaptive bias control circuit for use with a radio frequency (RF) power amplifier, said RF power amplifier having an input for receiving an input signal having a varying amplitude, an output, a first transistor having a first, second and third terminal, and a plurality of operating performance characteristics responsive to a quiescent operating point established by a bias current in the RF power amplifier, said bias control circuit comprising:a first circuit coupled to said RF power amplifier for receiving a portion of said input signal; and a second transistor for generating a rectified signal from said portion of the input signal, said rectified signal for causing said bias current to be controlled as a function of the amplitude of the input signal, said second transistor having a first and second terminal directly connected together and coupled to said first circuit and a third terminal coupled to a fixed voltage.