S-band coaxial vircator with electron beam premodulation

Summary form only given: The concept of a double-section coaxial vircator with radial electron beam injection and electrodynamic feedback was developed. The use of electron beam premodulation in the vircator allows an increase in efficiency and ensures a single- mode regime of TEM wave generation. The vircator operates without external magnetic field, features comparatively low (about 15-20 Ohm) operating impedance of the vacuum diode, and makes feasible wide-band frequency tuning through varying the resonator parameters. Vircator was simulated by using the PIC-code KARAT. For optimum regime generation, the simulated microwave power was about 3 GW with 12 - 15 % efficiency at 2.2 GHz, frequency tuning band at half power level - about 20 %.