| This thesis deals with the design of class E switching-mode power amplifiers (PAs) intended for improvement in the power efficiency of emerging wireless radios. Comprehensive theoretical analysis of class E amplifiers was carried out to develop an adequate design procedure. Three different circuit topologies (classic, low pass and optimized second harmonic) for the realization of class E PAs were studied, and their performances were evaluated based on RF simulation results. Accordingly, a compact, low-loss and multi-harmonic load network was chosen to design and build two class E PA prototypes operating at 1GHz and 2GHz. The proof-of-concept prototypes were built using a 10-watt gallium nitride transistor. Their performance evaluation revealed excellent power-added efficiency of about 80.8% and 70.5% at 1GHz and 2GHz, respectively, for an output power of approximately 10 watts. Moreover, very good second and third harmonics suppression, in excess of -62 and -75dBc (second harmonic), and -47 and -40 dBc (third harmonic), was achieved for the 1GHz and 2GHz prototypes, respectively. |
