Beam-steering Transmitarray Antenna for 5G Application

In this work, a linearly polarized, high gain, low profile, symmetrical metasurface-based transmitarray antenna is presented. To design the transmitarray, two RT/duroid 5880 substrates of thickness 0.787 mm are sandwiched between three conducting layers. The geometry of conducting layers in the unit cell is altered accordingly to obtain the desired phase shifting characteristics. These unit cells are then arranged in a particular fashion, obtained from the phase difference equation, to make the transmitarray. The transmitarray is illuminated by a 2x2 microstrip patch antenna array placed at the focal distance (D = 43.2 mm). The F/D ratio of the design is 0.8 which makes it a low-profile antenna. Beam-steering is achieved by moving the feed source along the focal plane. The design transmitarray antenna operates in 25.2-30.5 GHz (BW=19%) band having bandwidth 5.3 GHz. The simulation results show a maximum gain of 17.7 dBi in the broadside direction, scan angle is 46 degrees (-23 degrees to +23 degrees) in both the E-plane and H-plane, with a scan loss of 1.45 dB.