Coupled-mode theory of coaxial gyrotron with two electron beams

Results of coupled-mode theory for the study on coaxial gyrotron with two electron beams (CGTB) are given. The beam–wave interactions of single-mode and dual-mode CGTB are discussed in details. Compared with the coaxial gyrotron with one beam (CGOB), the dual-mode CGTB has distinguished advantages: the fundamental and high harmonic can be enhanced due to the coupling between two beams.