Multi-kW sheet beam amplifiers at Ka and W bands

NRL's unique sheet-beam electron gun, which produces a 3.5-4-A, 0.3 × 4 mm electron beam at ~20 kV, has been successfully used to power multi-kW amplifiers at both Ka and W bands. The 94-GHz narrow-band EIK uses a 3-cavity circuit to produce a peak output power of over 7.5 kW, with saturated gain of ~35 dB. The Ka-band amplifier uses a double staggered ladder coupled-cavity circuit to achieve a peak output power >10 kW at 34 GHz, with a 3-dB bandwidth of 5 GHz and saturated gain of ~15 dB. The performance of both amplifiers is in very good agreement with models and simulations.