Development of a Relativistic Magnetron with TE11 Output Mode for High Power Microwave Applications

A relativistic magnetron with a novel diffraction output has been analyzed with 3D particle-in-cell simulations. Using a six-cavity relativistic magnetron with a cylindrical cathode, the generated microwaves are propagated through a diffraction output tapered with four radially opposite cavities, to produce a TE11-mode in a cylindrical waveguide at the output. The performance has been evaluated for different input coaxial line radii, voltages ranging from 185 kV to 330 kV in the anode-cathode gap and applied magnetic fields generated by a Helmholtz pair from 0.26 T to 0.32 T. Results show successful and efficient TE11 operation. An efficiency maximum of 46% is found for an axial magnetic field of 0.32 T and a voltage of 270 kV, generating an output microwave power of 0.36 GW at 2.57 GHz. Also, the electron leakage current is found to be 10% of the total current. These results motivate continued interest in the relativistic magnetron with diffraction output for high power microwave applications.