Wristwatch-Style Wearable Dielectric Resonator Antennas for Applications on Limps

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.