Demonstration of a Reflectarray With Near-Field Amplitude and Phase Constraints as Compact Antenna Test Range Probe for 5G New Radio Devices

In this work, a reflectarray is proposed to be used as a probe of reduced and portable compact-antenna-test range for 5G new radio devices. The reflectarray works at 28 GHz and produces a quiet zone in the near-field region of the antenna. Considering that the quiet zone specifications are established in terms of the amplitude and phase ripple, a synthesis technique is presented to optimize the near field in the Fresnel region of a reflectarray with amplitude and phase constraints. The proposed technique is based on the generalized intersection approach using the Levenberg-Marquardt algorithm as its backward projector obtaining a novel technique in near-field synthesis. This technique is applied to improve the quiet zone radiated by the proposed reflectarray, overcoming the amplitude and phase limitations of the initial configuration. The solution provided by this process is used to design and manufacture a reflectarray based on a three-parallel-dipole cell. Finally, the prototype is measured in a near-field planar range facility in order to evaluate the radiated quiet zone and demonstrate the methodology. The prototype satisfies the tight requirements in amplitude and phase, obtaining promising results.