Third-harmonic TE/sub 411/ gyroklystron amplifier

A design for a high-gain and efficient harmonic gyroklystron is presented. Competing modes are suppressed by slicing the smooth-bore circular waveguide cavity to interrupt their wall currents. The guiding center of the moderate voltage electron beam from a magnetron injection gun is placed near the maximum of the operating third-harmonic TE/sub 41/ interaction and the minimum of the strongest remaining competing modes. Simulation predicts an output power of 70 kW with 30-dB saturated gain and 20% efficiency.