Simulation and Analysis of S-band Compact Relativistic Magnetrons

keywords:high power microwave  relativistic magnetron  lotus leaf-type output structure  TEM mode  full electromagnetic

Abstract:A relativistic magnetron with a coaxial output in the S-band that operates efficiently under low magnetic field conditions has been designed for miniaturized high-power microwave devices. The lotus leaf-type output structure is used to directly extract high-frequency field energy, making the device more compact in radial size. A cathode cap is introduced at the input side to further constrain the axial drift electrons in the high-frequency field region, allowing for sufficient conversion of high-frequency field energy and achieving higher output power and conversion efficiency, while enhancing the stability of the device′s operation. A three-dimensional model is built in CHIPIC, a full electromagnetic particle simulation software, to analyze the effects of different sizes of the lotus leaf-type output structure on the output performance of the magnetron. After the optimized design, the simulation results show that this relativistic magnetron has an output power of 200 MW and a power conversion efficiency of 44. 3% at an operating voltage of 180 kV and an applied magnetic field of 0. 27 T. It operates at an operating frequency of 2. 425 GHz, with an output mode of TEM mode.