Design of MW-Class L-Band Magnetron with TE11 to TE10 Mode Converter

A magnetron is a representative signal source for vacuum electron devices. This paper describes the design of L-band magnetron for mega-watt (MW) power output. First, the radius and the length of the cathode are designed based on the required output current. The number of cavities in the anode is determined to be 12, and the length of the anode is designed to be approximately quarter wavelength. The remaining design dimensions of the anode are also presented in reasonable design way. We perform particle-in-cell (PIC) simulation using CST-particle studio (PS) tool and confirm that pi-mode spokes are formed. We design and measure an antenna and a mode converter that deliver the amplified signal of the magnetron to the outside. The designed antenna is a type of the dipole, and the output mode is converted from TE11 to TE10 and deliver to the WR-650. The final output of the magnetron confirmed by simulation is 1.26 MW with 1.3 GHz oscillation. The anode output efficiency including the mode converter is about 34%. Based on the simulation and the cold test results, it is expected that the magnetron can be successfully manufactured.