Using Reconfigurable Transmitarray to Achieve Beam-Steering and Polarization Manipulation Applications

A reconfigurable transmitarray with beam steering and polarization manipulation capabilities is presented. The transmitarray element consists of an active side, a 360 degrees reflective phase shifter, and a passive side. The active side is made of a polarization tunable patch structure, which can radiate electromagnetic wave at dual linear polarization. The passive side composed of a two-layer patch structure is unitized as a receiver cell. We adopt 8 x 8 unit cells to construct the whole transmitarray, and then place it above a horn antenna. The measured results show that the transmitarray-based horn antenna achieves beam steering with the scan range of +/-60 degrees x +/-60 degrees at 5.4 GHz, and this steering capability can be realized in two orthogonal linearly polarized modes. The polarization manipulation capability of this transmitarray is then studied, and it is found that four different output polarization modes, including two circular polarizations [right-handed circular polarization (RHCP) and left-handed circular polarization (LHCP)] and two linear polarizations, can be obtained over an 8.5% fractional bandwidth, with cross-polarization ratio larger than 15 dB.