SIMULATION OF FIELD-EMISSION MICROTRIODES

Vacuum microtriode RF amplifier performance, based upon a unit cell with a conical field emitter tip, gate, and anode, was evaluated via computer simulation. Electron emission was calculated from the Fowler-Nordheim equation. The dependence of emitted current, transconductance, and field enhancement upon geometrical factors, e.g., tip sharpness, tip height, cone half-angle, and gate hole radius, is shown. The device design parameters of transconductance, cutoff frequency, small signal gain, and efficiency, have been calculated. Electron streamlines and current flux are shown for time-dependent RF input. Because a compact electron beam source has wide application, the normalized beam emittance, brightness, and beam quality are calculated for a typical case. Potential difficulties with anode power deposition are noted.