Methods to produce short-pulse high-power microwaves

A comparison of the radial distribution of output HPM power produced by a relativistic magnetron driven by a traditional solid cathode and recently invented transparent cathode was performed. The transparent cathode was found to improve relativistic magnetron operation by providing faster start of microwave oscillations at a predetermined mode without mode competition. Comparison of output microwave pulses produced by the microwave pulse compressor equipped with a mechanically operated switch and a fast gas-discharge switch showed that the latter one sufficiently shortens the rise time of the output microwave pulse. Results of this research suggest that: i) the use of a transparent cathode in relativistic and, probably, nonrelativistic magnetrons provides better mode selection by locking the desired magnetron oscillations in a shorter period of time, and ii) the use of a faster switch (as fast as possible) in a waveguide of a microwave pulse compressor shortens the rise time of the compressed output microwave pulse.