Experimental study on folded waveguide traveling-wave tube

The folded waveguide traveling wave tube (FWTWT) is one of the alternative candidates for robust and high power mm-wave sources with the advantages of simple coupling, robust structure, and reasonably wide bandwidth. On the basis of Pierce linear theory and the special features of an E-plane folded waveguide as a periodic structure, the design of FWTWTs using linear electron beams, is uniquely defined by five parameters: center frequency, operation voltage, current, beam radius, and space harmonic number. To verify the validity of this method, a Ka-band FWTWT using a 12 kV, 150 mA electron beam, is designed and constructed. Measured and simulated results are compared.