Measurement of Loss Distribution of Clamping Rod in K-Band Helix TWT

Based on the electromagnetic field characteristics of TE10 mode of rectangular waveguide,a loss distribution measurement module of clamping rod in K-band helix traveling wave tube is designed.The loss parameters of the clamping rod are measured in microwave by transmission method.The measurement system eliminates the influence of reflected loss by calculating two transmission parameters,S₁₁and S₂₁,and obtains the loss distribution of attenuation coating along the axis.A sample of the clamping rod loaded with two-stage attenuators is measured in K-band.The attenuation distribution obtained more accurately reflects the regularities of loss distribution of the attenuator than that obtained by directly measuring the resistance.It is of guiding significance to the design of the attenuator.