title: Suppression of the asymmetric modes for experimentally achieving gigawatt-level radiation from a Ku-band Cerenkov type oscillator.
abstract: We present the analysis and suppression of asymmetric modes in a Ku-band Cerenkov-type oscillator numerically and experimentally. The asymmetric modes generated in the initial experiments were identified to be HE11, HE21, and HE31 modes, respectively, by analyzing of the dispersion relationships, the simulation results and the experiment phenomenon. The factors, such as the cathode emission uniformity, the diode voltage, guiding magnetic field, and the concentricity play key roles in the excitation and suppression of these asymmetric modes. In the improved experiments, the asymmetric modes were suppressed effectively. In the improved experiments the asymmetric modes are suppressed effectively, and the designed TM01 mode microwave is generated at a frequency of 13.76 GHz with a power of 1.1 GW, which is in good agreement with numerically predications.
authors.affiliation: College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Shu
authors.affiliation: College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073, People's Republic of China.
authors.forename: Jinchuan
authors.initials: J
authors.lastname: Ju
authors.affiliation: College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073, People's Republic of China.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Wu
authors.affiliation: College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073, People's Republic of China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Bai