High power aluminum nitride RF vacuum window

Summary form only given. Aluminum nitride (AlN) is a leading candidate for replacing BeO or high-purity alumina as an RF window material because of its good mechanical and electrical properties. However, forming a vacuum tight AlN-to-metal seal has, until recently, proven difficult. Sienna Technologies has created a metallization technique to allow AlN to be used as a window ceramic and, jointly with L-3 Electron Devices, developed a braze process to hermetically seal the metallized AlN to copper. As an example, an S-band RF output window, suitable for incorporation into a high power microwave klystron, was designed by L-3 Electron Devices using CASCADE.