Characterisation of the Impact of Reradiation Interference on Transmission Lines Based on Characteristic Mode Theory

The reradiation interference of transmission lines to nearby radio equipment is affected by many factors, among which the pylons and ground lines in transmission lines have a greater impact on it. In view of the reradiation interference generated by transmission lines, it is proposed to study and analyse the different characteristic modes of transmission lines based on the theory of characteristic modes when the angle of transmission lines and the distance between stalls are changed. According to the single-tower equivalence model, the transmission line model with five towers is established, and then based on the Characteristic mode theory, the existence of ground wires in the transmission line and several Characteristic modes of the transmission line after the change of tower spacing are calculated, and the first three transmission lines with great influence on the transmission line are selected to analyze the existence of the induced current circuit and the distribution of the characteristic modes. The results show that the ground wire has a great influence on the reradiation interference of the transmission line, and when the tower distance of the transmission line changes, the reradiation interference of the transmission line changes. The reradiation interference value of the observation point can be reduced by adjusting the tower spacing and tower structure of the transmission line, so as to suppress the interference of the transmission line to the surrounding radio equipment.