2025 Volume E108.B Issue 4 Pages 421-430
This paper investigates the terminal voltage response of non-uniform two-conductor transmission line by uniform plane wave illumination. The presence of the insulating medium leads to non-uniform dielectric constant around the conductor in the case of non-uniform two-conductor transmission line formed by a wire wrapped in insulating medium and ground, resulting in the difficulty in distributed capacitance calculation. A method is proposed to calculate the distributed capacitance of non-uniform two-conductor transmission line based on S-parameters measurement in this paper. Subsequently, the proposed method for distributed parameter calculation is combined with the terminal response theory of two-conductor transmission line by external field illumination. The terminal response of non-uniform two-conductor transmission line by uniform plane wave illumination can be estimated according to S-parameters measurement results through this approach. The proposed method is implemented and analyzed using numerical computation software and validated with CST simulation results. Finally, the accuracy of the proposed method is verified by field line coupling experiment using GTEM cell. The results show that the terminal voltage responses of the non-uniform two-conductor transmission line by uniform plane wave illumination can be estimated by the S-parameters measurement.