Backward wave oscillator using a planar helix slow-wave structure with straight-edge connections

A novel BWO based on a planar helix slow-wave structure with straight-edge connections is presented. Simulation results show that the operating frequency of the BWO varies from 15.5–20 GHz when the beam voltage is tuned from 4.5 KV to 9KV. A cylindrical annular electron beam is applied to improve the interaction between the beam and the em field.