Abstract: A design for a field emission device comprising a cold cathode emitter, a control gate and a focus gate, is discussed. The focus gate is connected to the emitter voltage source and a ballast resistor is inserted between this connection point and the emitter. This ensures that the focus gate will always be more negative than the emitter, this difference in potential increasing with increasing emitter current. This leads to a linear current-voltage characteristic for the device and also makes for a tighter electron beam than that provided by designs of the prior art, A physical realization of the design is described along with a cost effective method for manufacturing said physical realization.