The Analysis of Passive Interference on the Shortwave Broadcasting Direction-Finding Station from High-Voltage Transmission Lines
摘要
To evaluate the interference of the Qingdao 220/500 kV high-voltage transmission line on the proposed antenna site, this study employed a commonly used line-surface hybrid analysis model for passive interference. The analysis and prediction of passive interference caused by the transmission line on the receiving station and direction-finding station in the target section were conducted. To simplify the calculations, a 5-base iron towers high-voltage transmission line model was utilized as a substitute for the entire transmission line. The analysis results indicate that: the maximum interference levels at Site 1 and Site 2 are −0.0917 dB(V/m) and −0.1262 dB(V/m), respectively, which are significantly lower than the 0.4 dB threshold specified in the standards. Furthermore, under the assumption of maximum electromagnetic wave incidence, it was found that the directional error caused by passive interference from the transmission line on the proposed direction-finding antenna meets the requirement of 1° as specified in the standards for frequencies above 3 MHz. The findings of this study provide valuable insights for the selection of antenna sites and the implementation of electromagnetic interference mitigation measures.