S-band Two-gap Metamaterial Extended Interaction Oscillator

In this paper, an S-band two-gap metamaterial extended interaction oscillator (MEIO) is proposed. The simulation results of electromagnetic properties indicate the effective characteristic impedance of the metamaterial extended interaction resonant cavity (MEIRC) is higher than that of conventional counterparts. Further, the beam-wave interaction results of the MEIO with the MEIRC show the output power is 2.5 MW and the electronic efficiency is 21.4% at 2.76 GHz for a beam voltage of 130 kV and a beam current of 90 A. The transverse and longitudinal dimensions of the interaction structure of the MEIO are 0.3λ and 0.6λ (λ is the wavelength in free space), respectively. As a miniaturized microwave source, the MEIO can provide for applications of high power relativistic klystron amplifier.