Double-gated field emitter arrays for microwave devices

After having a brief discussion on two kinds of structures of double-gated field emitter arrays (DGFEAs), presented in the paper are the design and simulation methods of the DGFEA, and simulation results of its emission characteristics and focusing performance. The results show that by properly introducing a focus gate above a control gate in the FEA, the DGFEA with an aperture focusing structure will produce a parallel electron beam, and its focusing performance can be effectively adjusted through the focus gate voltage; the additional focus gate lowers the array´s emission, but after improvement the maximum emission density of the DGFEA (with a control gate aperture of 1 μm and tip spacing of 3 μm) may exceed 500 A/cm²