Wristwatch-Style Wearable Dielectric Resonator Antennas for Applications on Limps

Ma Boyuan,Enhao Wang,Jin Pan,Deqiang Yang

doi:10.1109/access.2020.2983098

Abstract

A wristwatch-style wearable dielectric resonator antenna (DRA) is proposed for the 2.45-GHz ISM band and sub-6 GHz 5G NR bands around 2.5 GHz, such as the commercial band for China Mobile Communications Corporation. The antenna is designed for applications on forearms and ankles. Practical concerns, including the aligning method, platform size, specific absorption rate, and user effects are investigated. Coplanar feeding structure is applied for alignment and isolation. Analysis of the watchband-like substrate is highlighted to avoid performance degradation. Given that platform configurations are not discretionary in actual devices, parasitic loading is introduced to attain desirable substrate effects and suppress unwanted ones. The user-device interplay is studied in light of actual application scenarios. The specific absorption rate is calculated through multilayer biological tissue models. Meanwhile, radiation variation caused by users is estimated based on human phantom models and measurements.

Highlights

Dielectric resonator antennas (DRAs) are extensively investigated and applied to wireless devices because of their high efficiency, wide bandwidth, and flexible dimension, [1]–[4]
The fundamental theory of DRAs is established mostly based on flat platforms [5], so that these three-dimensional antennas are compatible with the printed circuit board technology
Platform and user effects on conformal wearable DRAs in actual scenarios are studied in detail

Summary

INTRODUCTION

Dielectric resonator antennas (DRAs) are extensively investigated and applied to wireless devices because of their high efficiency, wide bandwidth, and flexible dimension, [1]–[4]. The DRA and substrate are made of ceramic materials (εr_dr = 12.3, tanδ = 0.00014; εr_sub = 5.8, tanδ = 0.0015) It provides vertical polarization which is suitable for near-ground applications. The average specific absorption rate (SAR) is evaluated by placing the wearable DRA on two multilayer biological tissue models with different electromagnetic parameters and mass densities in each layer, as seen in Fig. 10 and 11.

FABRICATION AND MEASUREMENT

CONCLUSION