A novel EBG structure with spiral line bridges for radiation suppression in marine VHF band

The very high frequency (VHF) marine communication band (156-165 MHZ) is consequential for ship navigation safety, having the radiation limitation of 24dB·μV/m in this band and 54dB·μV/m in the adjacent band. The existing technologies are not enough to achieve targeted suppression of the radiation disturbance in this frequency band at PCB-level, which is equivalent to imposing strict limits on the whole test frequency band, making it necessary to pay an extra cost to achieve electromagnetic compatibility of marine electronic equipment. A spiral line bridged electromagnetic band gap (SL-EBG) is proposed for the radiation suppression of the marine VHF band. Based on the calculation of parasitic parameter, the equivalent circuit of SL-EBG is modeled; simulation and measurement are also performed to analyze the characteristic of SL-EBG. The stopband of the proposed EBG structure is 100MHz-300MHz, which S21 parameter is -27dB for two units, -59dB for four units and -72dB for five units at 160MHz.