SYSTEM AND METHOD FOR IMPROVING INPUT RETURN LOSS IN RF AMPLIFIERS

A system and method for improving the input return loss in RF amplifiers is disclosed. One embodiment of the present invention amplifies only one of the two output quadrature signals of 3 dB coupler in an amplifier module while substantially maintaining a constant impedance at the input to the 3 dB coupler. This removes one of the design constraints for designing the input network for an amplifier module thereby allowing for more flexible amplifier designs and ease of cascading amplifier modules. One embodiment of the present invention improves the input return loss of an RF amplifier pallet in a cascaded-stage power amplifier circuit for a television transmitter including a 3 dB coupler by replacing one of the two amplifiers connected to the output of the 3 dB coupler with an electrical circuit of substantially equivalent impedance to the input impedance of the non-replaced amplifier.