Low-Profile Transmitarray Antenna with High Selective Gain Filtering Characteristic

In this paper, a novel low-profile transmitarray antenna with high selective gain filtering performance is proposed. The proposed transmitarray unit cell is comprised of a magneto-electric (ME) dipole and a split-ring resonator. The ME dipole provides radiation zero at low frequency, and the splitring resonator provides radiation zero at high frequency. The transmission phase of 0° and 180° can be realized by rotating the bottom feed structure in the radiation band. The thickness of the transmitarray unit cell is 3.1mm (0.106λ). Based on the unit cell, a circular transmitarray antenna with a center frequency of 10.3GHz and a diameter of 221.2mm <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(7.6\lambda)$</tex> is designed. The simulation result shows that the transmitarray achieves a 3dB gain bandwidth of 12.3%, the highest gain is 20.07dBi, the suppression level at low and high frequencies are 27.4dB and 17.7dB, respectively. And the calculated selectivity is 0.86. A high selectivity and low profile is implemented.