High power microwave generation by Cherenkov-cyclotron instability in a metamaterial structure with negative group velocity

摘要

We present the experimental results of a high power microwave source with a metamaterial structure designed at 2.4 GHz. The structure is a waveguide loaded with two metamaterial plates consisting of complementary split ring resonators placed in the waveguide with reverse symmetry. Two backward wave modes can propagate in the waveguide and interact with an electron beam of up to 490 kV, 84 A. Full microsecond long output microwave pulses up to 2.9 MW were measured with an efficiency of 9% from the Cherenkov-cyclotron instability.