Metamaterial-enhanced slow-wave structures for traveling wave tube applications

Summary form only given. The growing need for high power sources at millimeter wave (MMW) frequencies has been motivated by a number of applications ranging from high-data rate communication systems to homeland security and radar applications. Vacuum electronics amplifiers such as traveling wave tubes (TWTs) have superior power and efficiency capabilities at MMW and THz regions compared to solid state power amplifiers. However, at these frequencies, the extremely small dimensions of the slow-wave structures (SWS) used in TWTs limits their maximum beam diameter and beam current and consequently their gain and total output power levels. Therefore, at these frequency bands, it is desirable to increase the size of the SWS of a TWT without decreasing the primary frequency band of operation of the SWS.