A model is presented for a wideband gyro-traveling-wave-tube amplifier. The model’s output bandwidth is comparable to that of the existing wideband model, but its efficiency is improved a lot. In this model, after choosing a proper initial magnitude, the axial magnetic field has a slightly linear decrease from a given position in the interaction section. The interaction mechanism of the beam wave is analyzed and verified by numerical simulation. When the beam current is 7 A, voltage is 90 KV, the velocity ratio is 1.0, and the axial velocity spread is 2%, numerical results show a constant bandwidth of 20% with an efficiency of 42%; the peak power and gain are, respectively, 260 KW and 47 dB.

• Received 9 July 1999

DOI:https://doi.org/10.1103/PhysRevE.61.4450