AMC Integrated Multilayer Wearable Antenna for Multiband WBAN Applications

: In this paper, a compact, efficient and easy to fabricate wearable antenna integrated with Artificial Magnetic Conductor (AMC) is presented. Addition of slots and bevels/cuts in the rectangular monopole patch antenna yield a wide bandwidth along with band notches. The proposed antenna is backed with an AMC metasurface that changes the bidirectional radiation pattern to a unidirectional, thus, considerably reducing the Specific Absorption Ratio (SAR). The demonstrated antenna has a good coverage radiating away from the body and presents reduced radiation towards the body with a front-to-back ratio of 13 dB and maximum gain of 3.54 dB. The proposed design operates over a wide frequency band of 2.9 to 12 GHz (exceeding the designated 3.1 − 10.6 GHz Ultra-Wideband (UWB) band). The band notches were created using slots on the radiating patch in the sub-bands from 5.50 to 5.67 GHz and 7.16 to 7.74 GHz. The overall dimensions of the structure are 33 × 33 × 6.75 mm 3 . The antenna’s radiation performance increased considerably with the addition of the AMC layer. The SAR values for the antenna are reduced by 85.3% when the AMC is used and are 0.083 W/kg which is well below the FCC SAR limits. The simple design, miniaturized profile, low SAR and wide operating bands with multiple band notches make the presented antenna an appealing choice for several UWB wearable body area network (WBAN) applications. when the AMC metasurface is placed below it. The measured radiation pattern showed that the fabricated antenna has a good coverage away from the body and minimal radiation towards the body with a 3 dB beamwidth of 88 degrees. The simple design, miniaturized profile, low SAR and wide operating bands with multiple band notches outperforms other state of the art UWB patch antennas. The study fulfills the requirements of efficiency, compactness, unidirectional pattern and FCC SAR regulations. As the future of wearables is advancing towards sophisticated mm-wave bands and 5G-centric applications, a distinct model for wave propagation, system architecture and fabrication processes is required. The current manufacturing and fabrication methods can also be improved for wearable antennas to avoid deterioration in performance during production. The antenna can be translated into a flexible substrate and more precise fabrication techniques can be used such as conductive graphene, laser cutting, inkjet printing transition metallic niobium diselenide (NbSe2) and MXene ink.