A Microstrip Matching Network for Class C Power Amplifiers Optimization

The effect of second harmonic reactive termination on the performance of an UHF class C amplifier will be presented. A matching network that leads to an easy amplifier design for microstrip implementation will be described. With this network we can vary the fundamental and the second harmonic load impedance of the amplifier independently. With this circuit, significant improvements in the performance of a class C power amplifier were achieved by presenting proper values of second harmonic reactive load at the output of the transistor. Two experimental, hybrid prototypes with encapsulated discrete transistors were designed, mounted and tested to validate the design technique.