A Dual-Band CPW-Fed Circularly Polarized Antenna with Gain Enhancement Using FSS for Wi-Fi and Sub-6 GHz 5G Applications

A dual-band antenna resonating at 2.45 GHz and 3.46 GHz, tailored for Wi-Fi and sub- 6 GHz 5 G applications is presented. The antenna features a compact structure built on a CPW-fed rectangular patch on an FR4 substrate of dimensions <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$35 ~\text{mm} \times 35 ~\text{mm} \times 1.6 ~\text{mm}$</tex>. To achieve dual-band operation and circular polarization, the patch and ground are modified with slotted, truncated, and stub-loaded configurations. The antenna exhibits bandwidths of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2.24-2.82 \text{GHz}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.24-4.13 \text{GHz}$</tex> at the respective center frequencies, and circular polarization is observed at both bands. The antenna's gain at the center frequencies is measured at 2.2 dB and 2.8 dB, respectively. Furthermore, the integration of a Frequency Selective Surface (FSS) with a dual-ring unit cell, significantly increasing the gain to 6.9 dB at 2.45 GHz and 7.4 dB at 3.46 GHz. The gap between the antenna and FSS is optimized to 15 mm for peak performance. The proposed design demonstrates considerable improvement in gain and performance, making it a promising solution for modern wireless communication technologies, including Wi-Fi and 5G networks.