Electrons are field emitted from the surface of metals and semiconductors when the potential barrier that holds electrons within the material is narrowed and deformed by high electrostatic fields, which are typically obtained by the application of a bias voltage between a gate structure and a nanometer scale, high-aspect-ratio structure ended in a nanosharp tip. Due to their exponential dependence on tip radius, emission currents are extremely sensitive to tip radii variation. Consequently, only a small fraction of the tips in an array emit electrons when a voltage is applied between the gate structure and the emitters. Attempts to increase the emission current by increasing the voltage results in burnout and on-voltage up-shifting. Spatial uniformity can be maximized if the emitters are ballasted. Previous ballasting approaches used large resistors in series with field emitters, but this resulted in power dissipation in the resistors and low emission currents from the array.