An Extremely Compact Multibeam Folded Transmitarray Antenna Based on Reflectarray With Additional Phase Compensation

An extremely compact multibeam folded transmitarray antenna (FTA) with additional phase compensation in reflectarray is presented. The FTA is composed of a reflectarray and a transmitarray fed by 11 identical E-shaped patch antennas. The phase average technique is used in the design of the transmitarray to increase the beam coverage. In contrast to those conventional FTAs, the proposed FTA incorporates additional phase compensation in its reflectarray. This results in a reduction in the antenna profile while maintaining the height of the feed virtual image. Finally, an 11-beam FTA prototype has been designed, fabricated, and measured. Experimental results show that the FTA achieves a scanning range of ±30° and a gain of 21.98 dBi at 28 GHz. Owing to its features, such as low cost, low profile, and wide angular coverage, the proposed FTA is an optimal solution for mm-wave wireless communication.