LAUSR

Multibeam antennas have found more and more applications in current and future communication systems. In this letter, a low-profile multibeam fully planar folded transmitarray antenna (FTA) based on the bifocal principle is proposed. It consists of a reflectarray, a transmitarray, and a group of identical planar feeding antennas. The transmitarray is developed with the metasurface and achieves high transmission efficiency and 3 b compensation phases. A new technique is proposed to improve the isolations among the feeding antennas by taking advantage of the multiplicity of the feeding elements. As an example, a multibeam FTA operating at the Ku-band was designed, fabricated, and tested. Experimental results achieve a peak gain of 22.7 dBi and a scanning range of ±21°, with a maximum feed isolation of 24 dB.