Optimised high-efficiency Class E radio frequency power amplifier for wide bandwidth and high harmonics suppression

A Class E power amplifier offers high efficiency approaching 100% for an ideal case. A new wide bandwidth Class E power amplifier design has been introduced combining a parallel-circuit load network with reactance compensation technique and high-order harmonic suppression circuit. The proposed topology has been discussed based on theory and its experimental verification. A hardware prototype was designed and built, and measurement results showed drain efficiency of 70% and second harmonic rejection of more than 84 dBc (as well as higher harmonics), and output power level more than 6.5 W with ±0.5 dB power flatness, across very high frequency (VHF) band (136-174 MHz). The performance achieved demonstrated highest harmonic suppression across wide bandwidth for VHF range according to authors´ knowledge. Simulations of power performance (i.e. efficiency and output power) were verified by measurements, and good agreements were obtained.