AMC Integrated Multilayer Wearable Antenna for Multiband WBAN Applications

Iqra Aitbar,Akram Alomainy,Nosherwan Shoaib,Qammer H Abbasi,Muhammad Ali Imran,Abdul Quddious,Symeon Nikolaou

doi:10.32604/cmc.2022.023008

Abstract

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 mm3. 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.

Highlights

In February 2002, the Federal Communications Commission (FCC) has regularized the unlicensed wireless communication over the Ultra-wideband (UWB) range i.e., 3.1 to 10.6 GHz, with an Effective Isotropic Radiated Power (EIRP) level of −41.25 dBm/MHz [1]
Since the tissues on human chest are curvilinear in nature, care was taken to place the structure in such a way that the encapsulated button does not touch the human skin
To minimize the detuning effects from the human body, the module is backed with Artificial Magnetic Conductor (AMC) that provides shielding to the body, minimizing Specific Absorption Ratio (SAR), maintaining good impedance matching and maximizing antenna effectiveness

Summary

Introduction

In February 2002, the Federal Communications Commission (FCC) has regularized the unlicensed wireless communication over the Ultra-wideband (UWB) range i.e., 3.1 to 10.6 GHz, with an Effective Isotropic Radiated Power (EIRP) level of −41.25 dBm/MHz [1]. The Wearable antennas have to comply with challenging requirements related to radiations next to human body, which may cause frequency detuning due to lossy nature and high dielectric property of human tissues. These problems can be overcome through effective design techniques including the use of a metamaterial multi-layer stacking [3]. Frequency selective surface can use the ultra-wide stopband by way of reflectors for UWB antennas [4]

Methods

Results

Conclusion