A Circularly Polarized 3-D Printed Dielectric Transmitarray Antenna at Millimeter-Wave Band

In this letter, a novel elliptical cylinder dielectric resonator (ECDR) is proposed. By combining a square substrate and two symmetrical ECDRs, an ECDR element is formed, which can effectively achieve the transformation from the linearly polarized incident wave to the circularly polarized (CP) transmitted wave. By adjusting the height of the element, a linear transmission phase range over 360° can be obtained, which can reduce the fabrication difficulty and cost through a 3-D printed technology significantly. Meanwhile, the ECDR element has a low conductor loss in high frequency. Additionally, a CP 3-D printed dielectric transmitarray antenna at the millimeter-wave band is designed by employing the ECDR elements. It is found that the aperture efficiency is up to 40.3%, the 3 dB axial ratio bandwidth is 17%, and the 1 dB gain bandwidth is 13.3%, respectively. The measured results are in good agreement with the simulated ones. This may be the first time that a CP 3-D printed dielectric transmitarray antenna has been reported.