Electromagnetic design and analysis of a high power tunable pulsed magnetron using MAGIC-3D

This paper presents 3-D electromagnetic simulation of resonant system of a 2.6 MW, 2.998 GHz tunable pulse magnetron using Magic 3-D Code. This resonant system is a twelve resonator hole and slot type structure with echelon type strapping. Other parts include coupling loops, output seal and tuning mechanism. Coupling is through end mounted double loop with a dome type glass window. The capacitive tuner, connected to one of the side resonator, consists of metal bellow and a metal piston that can be moved in radial direction. π-mode frequency has been computed simulating position of the tuner to give minimum and maximum frequency values. Corresponding π-mode frequencies found are 2.953GHz and 2.970 GHz giving predicted tuning range of 17 MHz. the dispersion characteristic has also been obtained. The cold test model of the magnetron has been fabricated and experimentally characterized. Performance chart has been plotted using in-house computer program. Simulation results have been compared with experimental values and have been found in good agreement except `Q' values.