A C-band relativistic magnetron with multi-antenna output structure

A C-band relativistic magnetron (RM) with a multi-antenna output structure is designed. The magnet system of this structure is compact and can provide a much purer output mode. This paper deduces the relationship between the antenna position and the output power of the multi-antenna structure and theoretically deduces the antenna position with the maximum output power. In addition, the relationship between the output power and the antenna length is also derived. The results show that the maximum output power is achieved when the antenna length is approximately an integer multiple of half the wavelength. A C-band RM was designed for PIC simulation to verify the correctness of the theory. In addition, the sector antennas are designed to reduce the field strength near the end cap to below the breakdown threshold. The PIC simulation results demonstrate that a microwave power of 1.73 GW and an efficiency of 58.9% are generated at 4.16 GHz when the voltage is 600 kV and the magnetic field is 0.42 T.