Design and evaluation of a wearable circularly polarized antenna for WBAN applications

Wearable devices play a very important role in developing health management and treatment applications. Therefore, accurate and compatible antenna-based sensors for wearable devices, which should be supported through materials and new design techniques, are needed. In this study, a miniature, ultra-wideband, conformal, and circularly polarized antenna was developed for body-worn applications. The design is 50 x 50 x 0.8 mm3 in size on a Jean substrate. Thanks to the substrate, the antenna designed in this study becomes more flexible and thin. Slots with different lengths and defected ground structures were used on the radiating patch in the design. Thus, the reflection coefficients and impedance matching are improved. The bandwidth of the proposed antenna is 152.9% in the 2-15 GHz frequency band. Thanks to its UWB characteristics, it supports various applications such as WiMAX, WLAN, unlicensed ISM, and X-band. It has a 9.1 dBi peak gain and over 90% radiation efficiency. Moreover, it also has an axial ratio of 0-3 dB; it is circularly polarized throughout its bandwidth. Configuration analysis is done in detail utilizing Characteristic Mode Theory (CMT). CMT is used for systematically investigating the electromagnetic properties of the antenna configuration and avoids time-based simulation methods by trial and error. The SAR performance of this antenna was evaluated on a realistic human phantom in a simulation environment. In addition, using infrared thermography, the real-time effects were evaluated on a chicken breast in an experimental environment. Moreover, bending tests were performed on the antenna. Considering the obtained results, the effectiveness and high strength of this antenna in complying with the SAR threshold when faced with the demands originating from human body loading and structural deformations were verified. The simulation and measurement results support the importance of the proposed design and wearable body-worn devices for wireless body area network applications.

Journal

PHYSICA SCRIPTA

Year

2025

Volume

100

Issue

7

ISSN

0031-8949

eISSN

1402-4896

DOI

10.1088/1402-4896/addb8f

WoS UID

WOS:001500576300001