Design of shaped dielectric lens antenna for wide angle beam steering

A design method is presented for a dielectric lens antenna with a wide beam scanning angle necessary For collision avoidance radar and car-to-car communication in an ITS. First, a design method for an antenna with a superior wide angle beam scanning capability is presented by providing an aperture distribution satisfying the Abbe sine condition for wide angle beam scanning in the shaped lens design to accomplish an arbitrary aperture distribution. Aperture distributions and positions of radiators in the case of wide angle beam scannings are obtained. Next, for evaluation of wide angle beam scanning, antenna performances are compared with the well-known bifocal antenna. In the case of a bifocal lens antenna, it is found that there exists a limit to the realizability of lens surfaces when the lens thickness is large because of the limited number of designed lens points. Radiation characteristics are compared in an antenna with an aperture diameter of 20 wavelengths. In the case of small F/D ratios that can reduce the antenna depth, the shaped lens provides better gains and sidelobe levels than a bifocal lens. When the beam is steered Up to 30 degrees in a lens with F/D = 0.5, it is shown that the gain deterioration is 5 dB and the sidelobe level increase is 5 dB. (c) 2005 Wiley Periodicals, Inc.