In this paper we perform a safety assessment of portable self-protection, high-range and broadband electromagnetic devices. Such instrumentation is particularly common in military equipment, for instance in the form of back-pack systems. Our aim is to analyze the effect on human body of high-power and broadband radiating systems, especially considering their near-field operating region. Hence, differently from the typical approach in the literature, we design through a numerical electromagnetic solver a common back-pack device operating over a large bandwidth (40–2700 MHz), employing ad-hoc compact and broadband antennas. Moreover, we place close to this system a realistic body phantom model (Hugo) in order to accurately characterize the effects in terms of SAR deposition and hot-spots localization, considering the tissues dispersive properties. The results show that the SAR limits can be likely overcome by the typical power levels of these systems, thus requiring a careful safety assessment. Guidelines are provided in the manuscript in order to decrease the SAR levels by opportunely selecting the back-pack radiating elements position. This study can be helpful to serve as a reference to accomplish a complete and accurate analysis on the e.m. safety of similar devices and, further, to undertake suitable containment measures to reduce exposition.

中文翻译：

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便携式自我保护、高范围和宽带电磁设备的数值暴露评估


在本文中，我们对便携式自我保护、高范围和宽带电磁设备进行了安全评估。这种仪器在军事装备中尤其常见，例如以背包系统的形式。我们的目的是分析高功率和宽带辐射系统对人体的影响，特别是考虑到它们的近场工作区域。因此，与文献中的典型方法不同，我们通过数值电磁求解器设计了一个在大带宽（40-2700 MHz）上运行的通用背包设备，采用特设紧凑型宽带天线。此外，我们在该系统附近放置了一个真实的人体模型（Hugo），以便在考虑组织色散特性的情况下准确描述 SAR 沉积和热点定位的影响。结果表明，这些系统的典型功率水平很可能会克服 SAR 限制，因此需要仔细的安全评估。手稿中提供了指南，以便通过适当选择背包辐射元件位置来降低 SAR 水平。本研究有助于对类似设备的电磁安全性进行完整、准确的分析，并进一步采取适当的围堵措施，减少暴露。