A compact implantable antenna is proposed for wireless health monitor microsystem, which is operated in frequency of the Industrial, Scientific, and Medical (ISM) band. A circular radiator is cut four L-shaped slots and loading a shortpin between the radiator and ground plane to implement the circular polarization. Two crossed rectangle slots are etched on the ground plane so that the impedance and axial ratio (AR) bandwidths have been expanded at the same time. In addition, to further verify the performance of the antenna for biomedical application, we simulate a microsystem that monitors human health; and establish the simulation environment of the human heart and head. Then, we evaluated the performance of the microsystem in the human tissue simulation environment. The maximum specific absorption rate value satisfies the IEEE standard safety guidelines. The experiment results indicate that the impedance and AR bandwidths of proposed antenna are 2.25–2.78 GHz and 2.32–2.63 GHz, respectively. The total dimensions of π × 4 ² × 1.27 mm ³ are obtained, which is equivalent to π × 0.032 λ ₀ ² × 0.0102 λ ₀ ( λ ₀ is the free-space wavelength at 2.4 GHz). This compact size is very suitable for the application in health monitoring microsystem.

中文翻译：

---

用于健康监护仪微系统的宽带圆极化植入式天线

提出了一种用于无线健康监测器微系统的紧凑型可植入天线，该天线以工业，科学和医学（ISM）频段的频率工作。圆形辐射体被切割成四个L形槽，并在辐射体和接地层之间装入一个短销，以实现圆极化。在接地平面上蚀刻了两个交叉的矩形槽，以便同时扩展了阻抗和轴向比率（AR）带宽。另外，为了进一步验证天线在生物医学应用中的性能，我们模拟了一个监测人体健康的微系统。并建立人的心脏和头部的仿真环境。然后，我们评估了微系统在人体组织仿真环境中的性能。最大比吸收率值满足IEEE标准安全准则。实验结果表明，拟议天线的阻抗和AR带宽分别为2.25–2.78 GHz和2.32–2.63 GHz。总尺寸π×4 ^获得2 ×1.27 mm ³，相当于π×0.032 λ ₀ ² ×0.0102 λ ₀（ λ ₀是2.4 GHz的自由空间波长。这种紧凑的尺寸非常适合健康监测微系统中的应用。