A compact K-band slow-wave structure inspired by slot-ring metamaterial for high power microwave source

In this paper, we propose a metamaterial (MTM) structure that is suitable for use as a compact high power microwave device at K-band. A slow-wave structure (SWS) with an operating frequency of 25.36 GHz based on an all-metal MTM array was developed and studied in both simulation and experimental cold tests. The results show that this MTM SWS is very useful to miniaturize the high-power microwave device at K-band and control the electromagnetic field to release the energy into the TE11 mode. A particle-in-cell simulation model of a forward wave oscillator was built. With the optimized parameters, it shows that an output power of 118 MW and an electronic efficiency of 20% for a forward wave TE11 mode at a frequency of 25.36 GHz can be obtained for an applied voltage of 540 kV, a beam current of 1.09 kA, and a magnetic field of 0.25 T.