Body of revolution (BOR) FDTD solver applied to the analysis of lens antennas in receiving and emitting modes

This paper describes the implementations of a Body of Revolution (BoR) FDTD solver for the analysis and synthesis of the extended hemispherical lens antenna, in both receiving and emitting modes. The technique offers a faster solution for simulations involving the lens while maintaining the same level of accuracy compared to the 3-D FDTD method. In this framework, we studied both the homogeneous and inhomogeneous lenses. The near-field map is plotted to determine and compare the position, size and peak field value of the focal spot. We show that the introduction of hollow air cavity (inhomogeneous lens) enables reduction of the lens extension height to about 20% and make the whole structure 11% more compact. The compact lens shows good radiation pattern but with slightly higher side lobes level and broader main beam compared to the reference.