Simulation investigations of an efficient L-band bi-frequency MILO with ridged-disk-loaded interaction structure

Abstract

This article presents simulation studies of an L-band bi-frequency magnetically insulated line oscillator for its efficiency enhancement using a ridged-disk-loaded radio frequency (RF) interaction structure. The electromagnetic (EM) properties of the RF interaction structure implemented with conventional and ridged disk have been investigated with the aid of CST microwave studio suite. A comparative study between the EM properties of conventional slow-wave structures and ridged-slow-wave structures (RSWS) is presented. The impact of adding ridges at the tip of disks has been examined for its influence on the dispersion curve, phase velocity, and coupling impedance. The coupling impedance of the RSWS with ridged-disk-loaded vanes was found to be greater than that of the conventional SWS. Furthermore, influence on output power of the device is observed for different ridge's parameters. With the optimum dimension of ridge parameters, particle-in-cell simulation detects an high-power microwave at frequencies of 1.20 and 1.40 GHz, producing 3.8 GW of cumulative peak RF power with a conversion efficiency of 23.8%, when operated with a 420 kV input DC voltage and current of 38 kA.