Integrated Miniature Multiband Antenna Designed for WWD and SAR Assessment for Human Exposure

Brahim Fady,Jaouad Terhzaz,Abdelwahed Tribak,Fatima Riouch,Giovanni Andrea Casula

doi:10.1155/2021/5548834

Abstract

The article introduces a new, low-cost, integrated, multiband antenna design intended for wristbands and wearable wireless devices (WWD). With a miniaturized planar square-shape sizing 29 × 29 mm2, the antenna can fit easily inside WWDs. The proposed design covers the most used frequency bands such as LTE2300, ISM2400, LTE2600, WiMAX3500, WiMAX5200, and ISM5800 in which the antenna reaches up to −25 dB and 6.9 dBi in terms of S11 and gain, respectively. To evaluate the exposure amenability of design on human body, we studied the specific absorption rate (SAR) of the design in two main use cases: multilayered human wrist model and a SAM (Specific Anthropomorphic Mannequin) head model. In each use case, the SAR results in different positions for all frequencies are compared to FCC standards.

Highlights

Since 1999, wearable wireless devices such as smartwatches, bracelets, and smart glasses are becoming widely used in healthcare, industry, and mainly in everyday life [1]
These objects can communicate with the user by providing information in real time or generating conditional events, as in the case of the monitoring cameras which can on the detection of an intruder send an alert with photo to the user through his smartwatch, smart glass, or any similar wearable wireless devices (WWD)
Wu et al presented in [2] a multipleinput-multiple-output (MIMO) antenna design for a smartwatch in 5.2–5.8 GHz wireless applications. e proposed MIMO design has shown excellent performance in the Wi-Fi 5.2 and 5.8 GHz, but the other required technologies such as Wi-Fi 2.4 GHz, Bluetooth, and LTE are not covered, and the antenna must be embedded in the plastic watchstrap of the smartwatch presenting a constraint for the constructors

Summary

Introduction

Since 1999, wearable wireless devices such as smartwatches, bracelets, and smart glasses are becoming widely used in healthcare, industry, and mainly in everyday life [1]. E proposed MIMO design has shown excellent performance in the Wi-Fi 5.2 and 5.8 GHz, but the other required technologies such as Wi-Fi 2.4 GHz, Bluetooth, and LTE are not covered, and the antenna must be embedded in the plastic watchstrap of the smartwatch presenting a constraint for the constructors. Another MIMO antenna that relies on the smartwatch structure is developed in [3], where Wen et al designed a capacitive feed structure operating in Wi-Fi/ Bluetooth band. In each configuration we evaluate the SAR results at different positions for each frequency

Specification and Use Case

Antenna Design and Configuration

Results and Discussion

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SAR Studies