MILLIMETER-WAVELENGTH RELATIVISTIC MAGNETRON: PROBLEMS OF MICROWAVE POWER EXTRACTION

The relativistic magnetrons operating at millimeter wavelengths demonstrate problems with microwave power extraction, both in the radial and in axial direction. The preferred axial extraction concept can be implemented ei-ther as ‘diffractional output’ or via introduction of additional resonant elements into the output waveguide. In this paper several solutions for axial-directed extraction are discussed, including circular ring ‘antennas’ at the end of the anode-cathode space, and resonance-length rods at the faces of the anode-block cavities. These have allowed increasing the power extraction efficiency by a factor of 101 to 102.