Design of a power output unit for HF transmitters

In this paper, complete power output unit for an high-frequency (3-30MHz) transmitter system is presented. The system consists of a 4:1 power combiner block, a power control unit which is vital for the effective operation of the system and four commercially available power amplifiers. In order to achieve high-performance, we have focused on the design of power combiners and power control unit. To this end, modeling and analysis of power combiners are reconsidered and an efficient power combiner realization based on double-sided parallel-striplines is obtained. Using the proposed power combiners and the designed power control unit, the overall 1000W high-frequency output stage is built and its performance is verified via measurements results.