Spatially-Distributed Electron Beam Technology for Millimeter-Wave Amplifiers

This program is developing a multiple beam electron gun and magnetic focusing systems for a Ka-Band traveling wave tube (TWT) being developed by the Naval Research Laboratory (NRL). If successful, the program will improve the power density of the RF source more than a factor of five over existing technology. The electron gun will generate a 2 X 6 or 2 X 8 array of electron beams that will transfer power to the RF circuit. A primary focus of the program is to transport the beams using Periodic Permanent Magnet (PPM) focusing. This is particularly challenging for multiple beam devices; however, Phase I simulations indicate sufficient beam transmission can be achieved to meet specifications. Consequently, a prototype electron gun and magnetic circuit will be tested during the program. If successful, a prototype TWT will be built and tested at NRL. To reduce risk, the Base program will also investigate uniform field focusing with a permanent magnet. The goal of the program will be a compact, high power, Ka-Band RF source for mobile applications.