Linearization of microwave power amplifiers

This thesis presents results of research and circuit development of linearity enhancement devices for two classes of microwave power amplifiers, Travelling Wave Tube and Solid State Power Amplifier (TWTA and SSPA). It is shown that the TWTA is a prime candidate for linearization and significant improvements in channel linearity can be obtained by the use of a predistortion circuit. The Solid State Power Amplifier is also shown to benefit from linearization; although the improvement is not as dramatic as with the TWTA due to the inherently superior linearity performance of the SSPA.