Abstract:
This dissertation describes a new radio-frequency power-amplifier circuit and mode of operation that exceeds the efficiency of the conventional class C amplifier in the low and medium h-f range. It will be found useful in applications where linearity between the input and output are not required, as in all applications where a conventional class C amplifier would be used, and where the highest efficiency with regard to r-f power output for a given d-c input power is desired. The reasons for this high efficiency are the transistor operates in a pure switching mode, and the voltage across the transistor and the current flowing through it can both be made exactly equal to zero during the interval of the switch-on transient. A complete design procedure is given along with tabulated design parameters to simplify the numerical calculations. To illustrate this, a O-watt transistor r-f power amplifier was designed, built and tested in the laboratory. This amplifier was found to be so efficient that an external heat radiator on the power transistor was unnecessary. The author suggests that such a design could be used to advantage in a transmitter for a remote radio-navigation beacon, as an emergency marine life-boat transmitter or in similar applications where input power is limited and expensive to provide.
