A mm wave circularly polarized tri-band saucer shaped antenna for under water monitoring

In this article, we presented an mm wave circularly polarized tri-band saucer type patch antenna for drainage water monitoring. The antenna is designed to operate in an ultra-wide band at millimetre wave frequencies of 31.02 GHz, 40.3 GHz, and 56.98 GHz. To operate tri-bands, the proposed design comprises of five slits on four sides and lollipop-shaped splits carved in the centre of the patch. The designed antenna parametric analysis has carried out for optimized design. The proposed design is developed with the aid of HFSS software; we measured major parameters S11, VSWR, gain and radiation patterns in free space and underground environment were measured. The proposed antenna radiation pattern is observed and given in the results for E-plane and H-plane at various frequency bands and represented in results. The gain 3D polar plots and current circulation plots are also given at tri-bands and a comparative study is also presented. The overall system operates satisfactorily for under water monitoring purpose with considerable path loss.