Research on a high-efficiency V-band traveling wave tube with novel rectangular-ring vertex extended double-bar slow-wave structure

Abstract In this article, a novel rectangular-ring vertex extended double-bar (RR-VEDB) slow-wave structure (SWS) is put forward for high-efficiency V-band traveling wave tubes (TWTs). The proposed RR-VEDB can provide a significantly larger interaction impedance and thus achieve higher output power as compared to the conventional rectangular-ring vertex double-bar (RRVDB) SWS. The physical mechanism of the interaction impedance enhancement of the RR-VEDB SWS is revealed by analyzing the field distributions in detail. The particle-in-cell (PIC) simulation results predict that under the beam voltage of 21.6 kV and beam current of 0.2 A, the RR-VEDB TWT can generate a saturated output power of 676.06 W, corresponding to a gain of 41.31 dB and an electron efficiency of 15.65%. The output power, gain, and electron efficiency of the RR-VEDB TWT are significantly improved over the RRVDB counterpart with a slight reduction (≈1.5%) in 3 dB instantaneous bandwidth.