Active bias network circuit for radio frequency amplifier

Abstract

A bias network for a radio frequency signal power amplifier. A current source is connected to a source of band gap voltage and produces a current proportional to the voltage. A reference voltage circuit receives the current and produces a voltage which is proportional to the current, as well as changes in temperature. An operational amplifier is used to connect the reference voltage to the power amplifier, so that the power amplifier is effectively isolated from the reference voltage circuit and current bearer circuit. A power amplifier breakdown protection circuit is connected across the output of the operational amplifier for diverting avalanche current produced form the power amplifier away from the power amplifier when the power amplifier output is mismatched through the antenna. Baseband signal transmission from the power amplifier to the bias network circuit is also significantly reduced, thus avoiding the generation of spurious radiation components.

Dependencies are inferred from the claim text.