An Elliptical Cylindrical Shaped Transmitarray for Wide-Angle Multibeam Applications

A transmitarray antenna with an elliptical cylindrical shape is presented for a wide-angle multibeam radiation in this communication. The transmitarray has a cylindrical radiating aperture with an elliptical cross-section, namely, elliptical cylindrical shape. Multiple feeds can be placed on the middle horizontal plane to realize multiple beams. Inspired by a 2-D Ruze lens, the antenna shape and the phase compensation are jointly designed according to the desired maximal beam direction. Innovative methods including a feed refocusing analysis and a virtual focal length are utilized to achieve the phase compensation across the 3-D aperture for multiple beam radiations with a small scanning loss. In order to validate the proposed antenna, a prototype operating in the millimeter-wave (mm-wave) $E$ -band has been designed, fabricated, and measured. By changing the position of the feeding gain horn along the refocusing arc, the main beam of antenna can be scanned in 11 directions. The measured peak boresight realized gain is 27 dBi at 70.5 GHz and a beam coverage of ±43° with a less than 2.7 dB scanning loss is obtained.