Optimising RF linear Amplifier for maximum efficiency and linearity

Abstract

A method for increasing efficiency of radio frequency (RF) amplifier employing laterally diffused metal oxide semiconductor (LDMOS) transistors coupled to an RF exciter depending on the emission mode of modulated RF input signals generated by exciter, if exciter output signal is of a type where modulated RF signals do not have continuously varying envelope, biasing the LDMOS transistor in the RF amplifier with fixed quiescent drain current and fixed drain voltage supply to cause LDMOS transistors to operate in compression and if exciter output signal is of a type where modulated RF signals do have continuously varying envelope, biasing the LDMOS transistors in the RF amplifier for linear operation.