An X-Band Circularly-Polarized Marine Radar Antenna Based on Spoof Surface Plasmon Polariton

A novel X-Band circularly-polarized antenna for marine radar systems is proposed. Spoof surface plasmon polariton (SSPP) is used to convey slow waves as feeding transmission lines. A series of slotted circular metallic patches are used to radiate circularly-polarized wave. Since the top metallic patches are energized utilizing electromagnetic coupling, in order to achieve suppression of the side-lobe levels (SLL) lower than -20 dB, each patch is adjusted along the x-axis and the SSPP feed line. The simulation and measurement data both show that the antenna operating band is 9.1 to 9.65 GHz. In the marine radar antenna operating band (9.3-9.5 GHz), axial ratio is less than 3 dB and the gain is greater than 14.3 dBic. The proposed antenna has a wide range of applications in marine radars.