High-gain printed monopole antenna with dual-band characteristics using FSS-loading and top-hat structure

• Published in: Scientific reports Vol. 13; no. 1; p. 9982
• Main Authors: Danuor, Patrick, Moon, Jung-Ick, Jung, Young-Bae
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 20.06.2023; Nature Publishing Group UK; Nature Portfolio
• Subjects: Antennas; Cell surface; Impedance; Radiation
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-37186-x

In this paper, a printed monopole antenna with high-gain and dual-band characteristics for applications in wireless local area networks and the internet of things sensor networks is presented. The proposed antenna consists of a rectangular patch with multiple matching stubs surrounded to improve the impedance bandwidth of the antenna. The antenna incorporates a cross-plate structure which is seated at the base of the monopole antenna. The cross-plate consist of metallic plates aligned perpendicularly which enhances the radiations from the edges of the planar monopole to maintain uniform omnidirectional radiation patterns within the antenna's operating band. Furthermore, a layer of frequency selective surface (FSS) unit cells and a top-hat structure is added to the antenna design. The FSS layer consist of three unit cells printed at the back side of the antenna. The top-hat structure is placed on top of the monopole antenna and comprises of three planar metallic structures arranged in a hat-like configuration. The coupling of both the FSS layer and the top-hat structure presents a large aperture to increase the directivity of the monopole antenna. Thus, the proposed antenna structure realizes a high gain without compromising the omnidirectional radiation patterns within the antenna's operating band. A prototype of the proposed antenna is fabricated where good agreement is achieved between the measured and full-wave simulation results. The antenna achieves an impedance bandwidth |S | < - 10 dB and VSWR ≤ 2 for the L and S band at 1.6-2.1 GHz and 2.4-2.85 GHz, respectively. Furthermore, a radiation efficiency of 94.2% and 89.7% is realized at 1.7 and 2.5 GHz, respectively. The proposed antenna attains a measured average gain of 5.2 dBi and 6.1 dBi at the L and S band, respectively.