A compact TM01 mode combiner for phase locked high power devices

This paper presents the design of a circular waveguide TM01 mode combiner with high power capacity for phased locked high power devices. Considering the characteristic of the TM01 mode, two high power sources are injected co-axially into a radial waveguide structure with rectangular coupling apertures symmetrically placed on the cylindrical profile of the circular waveguide. The microwaves generated by two phase locked high power devices with the same phase are extracted by magnetic coupling. Then, the extracted microwaves travel through the rectangular waveguides separately, and are combined by the other radial waveguide with shorted wall. Circular cavities along the input waveguides are employed and provide reflections to eliminate the transmitted power from one source to the other and match the combiner. Simulation results show that the TM01 mode combiner at X-band possess GW level power capacity and combination efficiency up to 97%.