Five-way gyrotron power combiner

A high-power waveguide combiner for use with oscillator tubes in Ka-band is described. It combines five rectangular waveguide inputs into an overmoded circular waveguide output by a mode converting technique, which eliminates the use of a resonant cavity for the combining function, thus improving power handling. Input port isolation is good, but can be reduced to enable mutual injection locking of the five oscillators. When they are locked together, the output waveguide contains predominantly TE01-mode, allowing low-loss power transmission down a circular waveguide feeder.