Investigation on a coaxial HPM generator with low magnetic field

Abstract

A Ku band coaxial high power microwave generator with a low magnetic field was investigated without mode competition in this paper. Mode competition is avoided physically by adopting a two-cavity extractor instead of a three-cavity extractor to eliminate the resonance between the modulation slow wave structure and the extractor slow wave structure at any unexpected frequency except the working frequency. Moreover, the efficiency of the device increases due to the separation process of energy extraction and electron collection by adopting the inner conductor collecting structure. Particle simulation results showed that when the magnetic flux density is 0.6 T, the diode voltage is 560 kV, and the diode current is 8 kA, we get 1.55 GW microwaves with an efficiency of 35% and a frequency of 14.7 GHz. Experimental investigation is carried out based on the physical design and simulation results. 1.0 GW microwaves are obtained, and the frequency is 14.8 GHz in the experiment when the magnetic flux density is 0.64 T, the diode voltage is 590 kV, and the diode current is 8.5 kA. No obvious hint of electron emission or bombardment is observed at the surface of the generator after 10 thousand pulses, and the advantage of this kind of generator working in a low magnetic field is proved.