Study on Wide Power Dynamic Range Coherent Power Combining Based on S-Band 20-kW Frequency Pushing Magnetrons

A wide power dynamic range (WPDR) microwave power combining system based on two 20 kW continuous wave magnetrons has been studied. A WPDR power source is required in heating which microwave absorption of the materials is varying. This system includes two injection-locked S-band 20 kW continuous wave magnetrons with variable anode current. The frequency pushing characteristics are applied to the experiments. The anode currents are adjustable, and the phases of injected signal is automatic compensated by phase shifter to ensure a high efficiency power combining. According to the experimental results, the combining output power rang is over 13 kW, and the frequency of output signal stays constant. Furthermore, the measured combining efficiency is over 91%.