1-D Wide-Angle Beam-Scanning Linear Phased Array With Enhanced Gain by Using 3-D Printed Dielectric Slab Superstrate

A 1-D wide-angle beam-scanning linear phased array with enhanced gain by using dielectric slab superstrate (DSS) is presented. In this scenario, the beams of array elements in the scanning plane should be wide enough and that in the orthogonal plane should be as narrow as possible. Different from the existing DSS technology, the DSS in this letter is used to satisfy the requirements of the beams in both planes. The parameters of the DSS and its position are optimized by setting the narrowest beam in the orthogonal plane as the objective function under the constraint of the specified wide beam in the scanning plane. To validate the proposed scheme, an eight-element DSS linear phased array operating at 10 GHz was designed, fabricated, and measured. Using the simple measure, the measured 3.5 dB gain enhancement in the scanning range of ±43° has been achieved with the aperture efficiency of 98%, the low profile of 1.39 wavelength, and the acceptable side-lobe levels (SLL) of better than −8.7 dB.

I. Introduction

In microwave wireless communication, beam-scanning antennas with high gain are extremely important especially in the applications of millimeter-wave and terahertz technologies [1]. Superstrate technique is very attractive in antenna design for its enhanced gain. Compared with active superstrates [2]–[6], passive superstrates have the advantages of simple structure, easy of fabrication, low cost, etc. Many passive superstrates have been investigated such as homogeneous dielectric [7], perforated dielectric [8], quasi-periodic metal structure [9], and periodic metal structure [10]. They are often utilized to design high-gain antennas as lens antenna and resonant cavity antennas (RCA).