A Compact and Lightweight Relativistic Magnetron With Permanent Magnets

A novel S-band lightweight relativistic magnetron, packaged with permanent magnets and equipped with a compact axial extraction structure, is proposed. In this design, five alternately arranged anode vanes in a 10-cavity rising-sun magnetron are connected via a ring-like structure to enhance the π-mode coupling capability. This innovative ring extractor significantly reduces the overall radial dimension of the magnetron, making it consistent with the radius of the resonant cavity structure. Namely, the output structure introduces no additional radial size. Consequently, the proposed design effectively balances structural compactness and high conversion efficiency simultaneously. The reduced output aperture enables the use of a lightweight permanent magnet, bringing the total weight—including both magnetron and magnets—to only 20 kg. Finally, experiments have been conducted to validate the device’s performance, which demonstrates that, under a diode voltage of 172 kV, the proposed relativistic magnetron with permanent magnet achieves an average output power of 175 MW with a conversion efficiency of 30.8%. The combination of compact size and relatively high conversion efficiency makes this device particularly suitable for portable high-power microwave applications.