National Key Laboratory of High Power Vacuum Electronics, School of Physical Electronics, University of ElectronicScience and Technology of China, Chengdu 610054, China)(2.School of Physics, Seoul National University, Seoul, Korea, 151-747
A novel Folded waveguide (FW) ampli¯er for Traveling-wave tubes (TWT) was investigated. It is formed by adding rectangular grooves periodically to the bends of a normal FW. In order to test its performance, a three-dimensional Particle-in-cell (PIC) code MAGIC was used to simulate the large-signal beam-wave interaction. It proves to be a potential device for producing more than two times higher Continuous wave (CW) power with a much shorter circuit compared to a normal FW. The band per- formance is also good in above 2GHz. Furthermore, the novel FW e®ectively improves the problem that gain of a normal FW decreases at higher working frequencies due to diminishing of interaction impedance. This novel FW therefore promises a high power and miniaturized circuit for millimeter wave TWT.