Enhancement of off-body communications with a low-SAR, high-gain multiband patch antenna designed with a quad-band artificial magnetic conductor

The increasing demand for wireless communication has emphasized the need for multiband antennas. This study presents a novel design for a multiband antenna with reduced specific absorption rate (SAR), high gain, and improved front-to-back ratio (FBR) achieved through the integration with a 4 x 4 artificial magnetic conductor (AMC) surface. The proposed antenna covers a wide range of wireless frequency bands, including Industrial, Scientific, and Medical, Wireless Local Area Network, Worldwide Interoperability for Microwave Access, Wi-Fi 6E, and 7, with resonating frequencies at 2.4, 3.2, 5.5, 7.5, and 10 GHz. The AMC unit cell creates four zero-degree reflection phases with double negative properties at 2.5, 3.8, 5.5, and 7.5 GHz. The compact design measures 0.23 lambda 0 x 0.296 lambda 0 x 0.0128 lambda 0 and placed 0.104 lambda 0 above an AMC surface of size 0.512 lambda 0 x 0.512 lambda 0 x 0.1296 lambda 0. This structure enhances the gain by up to 8.55dBi at 6.01 GHz. The proposed antenna has -10 dB impedance bandwidth for these corresponding frequencies viz 2.34-2.43 GHz (3.77%), 2.81-3.83 GHz (30.72%), 4.82-6.21 GHz (25.20%), 7-7.65 GHz (8.87%), and 8.06-10.31 GHz (24.5%). An overall average percentage reduction value of SAR taken at these frequencies has been found to be 96.11% with AMC structure. The antenna sample was successfully fabricated, and the experimental results have been found to match well with the simulation results. This integrated design offers a promising solution for wearable off-body communication devices.