Ridge-Loaded S-Band MILO Using Drift Tube and Dual Extraction Cavity

Abstract

A magnetically insulated line oscillator (MILO) is a unique high-power microwave (HPM) device distinct by its inherent ability to generate a self-insulating magnetic field. In this article, an S-band ridge-loaded MILO is studied. The current design incorporates a drift section in a region of slow wave structure (SWS), resulting in a reduction of the axial velocity ( $v_{z}$ ) spread of the modulated beam. Another, a dual extraction cavity is designed in the extraction region. So, the axial electric field is enhanced, and beam-wave interaction is lengthened in this region; consequently, efficiency is increased. Dispersion characteristic is obtained in eigenmode analysis. In 3-D particle-in-cell simulation, the presented MILO generates a 4.5-GW average output power at 2.56-GHz frequency with an application of 500-kV voltage and a current of 42 kA. The average efficiency is elevated to 21.4%, while it is only 15.7% for conventional ridge-loaded MILO for the same input parameters, so the net increase in efficiency is 36%.