Simulations of a Shaped Dielectric Lens Antenna by FEKO

Abstract

In the Intelligent Transportation System (ITS), millimeter waves are used and antennas are requested to have beam scanning ability. In the millimeter wave operation, a dielectric lens antenna is one of the prominent candidates. Authors designed a shaped dielectric lens antenna based on the Abbe’s sine condition. Wide angle beam scanning characteristics were ensured through the ray tracing calculations and radiation pattern measurement. Recently, owing to the enhancement of electromagnetic simulator abilities, simulations of a dielectric lens antenna become possible. By employing an electromagnetic simulation, it is expected that detailed electrical performances of both the feed horn and the dielectric lens will be made clear. In this paper, electromagnetic simulations of a shaped dielectric lens antenna by FEKO suit 5.3 are conducted. First, the corrugate horn used for the feed horn is electromagnetically simulated. Excellent simulated radiation patterns coinciding with the measured results are achieved. Next, the feed horn radiation patterns are combined with the dielectric lens simulations. And simulation results of beam scanning characteristics are obtained. When comparing the simulated scanned beam shapes with the measured results, very good agreements are obtained. So, accuracies of simulations are ensured. Moreover, unexpected sidelobe increases in the specific wide angle region that were pointed out previously are studied. Simulated and measured results can confirm the sidelobe increases. As an additional study, electrical field distributions in the dielectric lens are simulated. Then, multiple reflections between lens surfaces are visually made clear. The reason of sidelobe increases can be clearly understood. As a result, it is confirmed that the FEKO simulator can rigorously simulate electromagnetic characteristics of a shaped dielectric lens antenna.