Abstract: Systems and techniques for return loss estimation are described. A forward power sample is taken from a power amplifier of a transmitter by sampling a feedback signal used for power control of the amplifier, and a reflected power sample at an output of the power amplifier is taken by observing the power at a circulator termination of the power amplifier. A difference determination is made for the forward power sample and the fleeted power sample in the analog domain to determine a return loss and may be digitized for further processing such as return loss measurement and comparison against thresholds. A further comparator circuit may be used to insure that measurements are made when the signal strength is adequate.

Abstract: A linearized amplifier comprising a RF input for receiving a modulated signal and a RF output for supplying a linearly amplified modulated signal. The RF input is connected to a first junction. The linearized amplifier further comprises a linearizer having an input connected to the first junction and a output connected to a second junction. The first junction defines a first path connected to the second junction through the linearizer for linearizing the modulated signal at a first defined range of power and a second path connected to the second junction bypassing the linearizer at a second defined range of power. The linearized amplifier further comprises a amplifier having a input connected to the second junction and a output connected to the RF output for supplying the linearly amplified modulated signal.