Gupta Anupma, Kumar Vipan, Bansal Shonak, Alsharif Mohammed H, Jahid Abu, Cho Ho-Shin
Department of Interdisciplinary Courses in Engineering, Chitkara University Institute of Engineering and Technology, Chitkara University, Rajpura 140401, India.
Department of ECE, Sri Sai College of Engineering and Technology, Badhani, Pathankot 145001, India.
Sensors (Basel). 2023 Aug 7;23(15):6989. doi: 10.3390/s23156989.
This study aims to design a compact antenna structure suitable for implantable devices, with a broad frequency range covering various bands such as the Industrial Scientific and Medical band (868-868.6 MHz, 902-928 MHz, 5.725-5.875 GHz), the Wireless Medical Telemetry Service (WMTS) band, a subset of the unlicensed 3.5-4.5 GHz ultra-wideband (UWB) that is free of interference, and various Wi-Fi spectra (3.6 GHz, 4.9 GHz, 5 GHz, 5.9 GHz, 6 GHz). The antenna supports both low and high frequencies for efficient data transfer and is compatible with various communication technologies. The antenna features an asynchronous-meandered radiator, a parasitic patch, and an open-ended square ring-shaped ground plane. The antenna is deployed deep inside the muscle layer of a rectangular phantom below the skin and fat layer at a depth of 7 mm for numerical simulation. Furthermore, the antenna is deployed in a cylindrical phantom and bent to check the suitability for different organs. A prototype of the antenna is created, and its reflection coefficient and radiation patterns are measured in fresh pork tissue. The proposed antenna is considered a suitable candidate for implantable technology compared to other designs reported in the literature. It can be observed that the proposed antenna in this study has the smallest volume (75 mm) and widest bandwidth (181.8% for 0.86 GHz, 9.58% for 1.43 GHz, and 285.7% for the UWB subset and Wi-Fi). It also has the highest gain (-26 dBi for ISM, -14 dBi for WMTS, and -14.2 dBi for UWB subset and Wi-Fi) compared to other antennas in the literature. In addition, the SAR values for the proposed antenna are well below the safety limits prescribed by IEEE Std C95.1-1999, with SAR values of 0.409 W/Kg for 0.8 GHz, 0.534 W/Kg for 1.43 GHz, 0.529 W/Kg for 3.5 GHz, and 0.665 W/Kg for 5.5 GHz when the applied input power is 10 mW. Overall, the proposed antenna in this study demonstrates superior performance compared to existing tri-band implantable antennas in terms of size, bandwidth, gain, and SAR values.
本研究旨在设计一种适用于可植入设备的紧凑型天线结构，其频率范围宽广，涵盖多个频段，如工业、科学和医疗频段（868 - 868.6 MHz、902 - 928 MHz、5.725 - 5.875 GHz）、无线医疗遥测服务（WMTS）频段、无干扰的非授权3.5 - 4.5 GHz超宽带（UWB）的一个子集以及各种Wi-Fi频谱（3.6 GHz、4.9 GHz、5 GHz、5.9 GHz、6 GHz）。该天线支持低频和高频，以实现高效的数据传输，并与各种通信技术兼容。该天线具有异步曲折辐射器、寄生贴片和开口方形环形接地平面。天线部署在皮肤和脂肪层下方7毫米深处的矩形体模的肌肉层内部进行数值模拟。此外，天线部署在圆柱形体模中并弯曲，以检查其对不同器官的适用性。制作了天线原型，并在新鲜猪肉组织中测量了其反射系数和辐射方向图。与文献中报道的其他设计相比，所提出的天线被认为是可植入技术的合适候选者。可以观察到，本研究中提出的天线具有最小的体积（75毫米）和最宽的带宽（0.86 GHz时为181.8%，1.43 GHz时为9.58%，UWB子集和Wi-Fi时为285.7%）。与文献中的其他天线相比，它还具有最高的增益（ISM频段为 - 26 dBi，WMTS频段为 - 14 dBi，UWB子集和Wi-Fi为 - 14.2 dBi）。此外，所提出天线的比吸收率（SAR）值远低于IEEE Std C95.1 - 1999规定的安全限值，当施加的输入功率为10 mW时，0.8 GHz时的SAR值为0.409 W/Kg，1.43 GHz时为0.534 W/Kg，3.5 GHz时为0.529 W/Kg，5.5 GHz时为0.665 W/Kg。总体而言，本研究中提出的天线在尺寸、带宽、增益和SAR值方面与现有的三频段可植入天线相比表现出卓越的性能。
