Abstract: Systems and methods for maintaining power amplifier performance are provided. A system includes a bias supply that generates a bias voltage, and at least one primary power amplifier (PA) that receives the bias voltage and a primary radio frequency (RF) input. The at least one primary PA amplifies the primary RF input based on the bias voltage. The system includes an auxiliary PA that is connected in parallel with the at least one primary PA and receives the bias voltage and an auxiliary RF input, which is a scaled version of the primary RF input. The auxiliary PA amplifies the auxiliary RF input based on the bias voltage. The system includes a detector that measures an output voltage associated with the amplified auxiliary RF input, and a comparator that compares the measured output voltage to a reference voltage. The bias supply adjusts the bias voltage based on the comparison.

Abstract: A circuit for a reflection-type variable attenuator may include a hybrid module including an input port, an output port, a first reflection port, and a second reflection port. The hybrid module may be configured to split an incident signal received at the input port into a first and a second input signal. A first and a second reflection circuit may be coupled to the first and the second reflection ports, respectively. The first and the second reflection circuits each may include one or more transistors, and may be configured to, respectively, reflect the first and the second input signals to generate a first and a second reflected signal, which are directed to the output port to be constructively combined to form an output signal that is an attenuated replica of the incident signal. A variable attenuation may be achieved by controlling amount of reflection through the reflection circuits.