Abstract:
Power amplifiers, being the most power hungry components in RF front ends,
have been a major area of research in Microwave Engineering. With increasing
competition and advancement of technology, a special focus of the engineering
firms has been on providing maximum efficiency and output power to the
customers at the lowest rates possible. In this regard, non linear Class F and Class
F
‐1 power amplifier have been found to be the most useful because of their ability
to achieve highest output power and maximum efficiency.
GaN based RF transistors have also gained ample recognition by many researchers
in recent times as opposed to LDMOS. Even though LDMOS is currently popular
for wireless and mobile communications, GaN based RF transistors have proven
their worth by providing higher break down voltage, higher efficiency, higher
power density and larger Bandwidth.
This thesis work is based on design and development of Class AB, Class F and Class
F
‐1 power amplifiers using GaN based transistors. In order to single out the most
efficient of all power amplifiers, a comparison has also been drawn between Class
AB, Class F and Class F
‐1 amplifiers. The said comparison was based on results
pertaining to output power and efficiency of each power amplifier. Class F
‐1
proved to be the most effective of all in terms of generation of maximum output
power (4.3 Watt) and maximum PAE (>68%). In addition to the above comparison
and result, effect of input harmonic termination on efficiency and output power
in Class F and Class F
‐1 power amplifiers was also investigated in this thesis.
Introduction of input harmonic termination resulted in increase of efficiency and
2 Abstract
output power by 12% and 0.3dB for Class F
‐1 power amplifier. While Class F power
amplifier efficiency and output power was enhanced by 4% and 0.2 dB
respectively
