Loss characteristics of the vaneloaded helical slowwave structures

In this paper, with the consideration of the radial thickness of the helix, the tape helix model is suggested for the vaneloaded helical slowwave structures. By taking the sicretesupports bars into some continuous dielectric tube regions, the expressions of attenuation constant are obtained. The effect on loss of the envelope, the vane and the helix material conductivity are all taken into account. This model can increase the calculated value of the attenuation constant. The results indicate that the loss of the helix occupies most of the whole loss.