IEEE Electron Device Letters · 2015 · 21 citations · 11 references
EngineeringElectrical EngineeringPhysicsMicroelectronicsMicrowave EngineeringPower ElectronicsCathode MaterialsHigh-frequency Power ConversionMicrowave MaterialsMicrowave OscillatorsOscillatorsGraphite AnodesHigh-power OscillatorsMicrowave DevicesPower DensityPyrolytic GraphiteShort-time Fourier TransformSpectrographsThermal Properties
Operation of repetitive high-power microwave (HPM) sources is predominantly limited by thermal properties of anode and cathode materials. This letter presents a reflex-triode virtual cathode oscillator (vircator) capable of operating at 500 Hz at current densities between 100-200 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> for multiple burst durations of 1-2 s. Stable vircator operation under such a thermally punishing environment is facilitated by the use of a thin pyrolytic graphite anode. The results presented focus on two anode-cathode (A-K) gap spacings: 11 and 21 mm, which produce stable microwave radiation at 4.6 and 1.6 GHz, respectively. Characteristic voltage, current, and microwave waveforms in conjunction with short-time Fourier transforms, frequency spectrographs, and HPM power density data for 1000 and 500 pulses at 1.6 and 4.6 GHz, respectively, are presented.
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Emission properties of different cathodes at E⩽105 V/cm
Ya. E. Krasik, A. Dunaevsky, A. Krokhmal et al. · Journal of Applied Physics · 2001 · 174 citations