The Effect of Ground Screen System on High-Frequency Surface Wave Radar Antenna Directivity

For quarter wave vertical antenna in high-frequency band, a ground screen system is indispensable. The ground screen is laid to reduce the effects by earth whose conductive is nonuniform and poor. High-frequency surface wave radar (HFSWR) system demands antenna directivity stricter than the radio station, so the system needs a high-quality ground screen system. This work examines the performance of the ground screen system for high-frequency antenna and finds applicable size and shape for antenna fabrication. Different ground screen sizes, densities and shapes are compared in the simulation for a 9.8 m tall monopole antenna in 7 MHz. The simulation results show that the size and density of the ground screen are important parameters for antenna, and radial ground screen performs better than latticed when the size of the ground screen is large. To find appropriate ground screen parameters for HFSWR, the analysis takes the effect of sea and coast into account. Furthermore, the results may provide guidance for ground screen laying in practical applications.