PPM focused TWT using a field emitter array cold cathode

Summary form only given. With the recent advances in field emitter array (FEA) technology, current densities as well as total currents from planar arrays have reached values meeting or exceeding many moderate power TWT beam requirements. The development of a robust high current density (>10 A/cm/sup 2/) cold cathode source, such as the FEA, would open new vistas in the power-bandwidth performance of microwave devices, particularly those operating at millimeter wavelengths. Extremely compact, lightweight, low frequency designs may also result with the advent of FEA gated emission cathodes. Before the development of such technologies, however, the challenges of FEA beam generation, focusing and confinement in a TWT PPM configuration must be solved. This experimental program is designed to address these issues. Several SRI field emitter arrays (known as Spindt cathodes) have been fabricated and tested for incorporation into a PPM-focused C-Band TWT.