Compact Wideband SRR-Inspired Antennas for 5G Microcell Applications

Abstract

This communication presents two novel designs of split-ring resonator (SRR)-inspired antennas with a low profile and a wideband response for fifth-generation (5G) microcell application. Two novel SRR structures are first presented and analyzed by their equivalent circuits. Then, an antenna with dual polarization inspired by the SRR is proposed. A thin metallic patch and metallic screws are used to construct this 3-D-SRR structure with low loss and cost. Two orthogonal coupling feed lines are designed to excite the orthogonal polarized radiation. Open stubs on the feeding lines are introduced to generate an additional resonant mode, resulting in an enhanced bandwidth which well covers the 5G-N78 band (3.3-3.8 GHz). Owing to the excellent miniaturization characteristic of the meta-resonator, a dual-polarized antenna with a very compact size of 0.231λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×0.231λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×0.044λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is achieved. Its measured peak gain and radiation efficiency are better than 4.7 dB and 83%, respectively. Finally, a circularly polarized (CP) antenna with good CP performance and a compact size is also implemented by the derivative crossed SRR. Overall, these two SRR-inspired antennas not only demonstrate miniaturization advantage but also show good radiation performance, rendering them suitable for the 5G new radio (NR) microcell station applications.