A Metasurface-enhanced Dual-resonant Antenna With Amc Backing for Sub-6 Ghz Iot Devices

This paper introduces a compact dual-band printed antenna, meticulously designed for efficient operation under the Sub-6GHz frequency spectrum, targeting the burgeoning field of Internet of Things (IoT) applications. Specifically, the antenna is engineered to exhibit enhanced performance at 4.2 GHz and 5.2 GHz, leveraging the synergistic integration of a strategically designed metasurface and an artificial magnetic conductor (AMC) backing. This combination aims to significantly improve both the antenna's gain and its operational bandwidth. The radiating structure features a carefully shaped tapered design, intricately embedded with stepped rectangular slots. This design forms a compact, multi-resonant geometry capable of supporting the desired Dual-Resonant operation. To ensure seamless integration into modern, low-profile IoT hardware, a coplanar waveguide (CPW) feed technique is employed, maintaining a planar configuration. The AMC layer, crucial for performance enhancement, comprises periodic unit cells incorporating complementary slot designs. These unit cells are meticulously tailored to achieve dual zero-phase reflection characteristics near the antenna's operating bands. This in-phase reflection mechanism leads to improved impedance matching and a more directional radiation pattern. The entire antenna structure is fabricated on a cost-effective single-layer FR4 substrate, occupying a compact footprint of 36 mm × 36 mm × 0.8 mm. In terms of electrical size, this corresponds to approximately 0.83λg × 0.83λg × 0.018λg at 4.2 GHz and 1.08λg × 1.08λg × 0.024λg at 5.2 GHz, where λg represents the guided wavelength at the respective frequencies. The design demonstrates impressive peak gains of 4 dBi and 6 dBi at 4.2 GHz and 5.2 GHz, respectively. The integrated metasurface and AMC backing work in concert to effectively suppress detrimental surface wave propagation, enhance forward radiation characteristics, and maintain the overall compactness of the antenna. With its advantageous small footprint, high efficiency, and dual-resonant operation, the proposed antenna emerges as a compelling candidate for integration into next-generation Sub-6 GHz IoT devices that demand reliable and high-performance wireless communication within stringent space constraints.