Yang Wendong, Cheng Xi, Zhao Xun, Wang Jia
Institut für Physik, Institut für Chemie, Center for the Science of Materials Berlin, Humboldt-Universität zu Berlin, Berlin 12489, Germany.
School of Electronic and Information Engineering, Liaoning Technical University, Huludao City 125105, China.
ACS Omega. 2024 Sep 12;9(38):39792-39803. doi: 10.1021/acsomega.4c05071. eCollection 2024 Sep 24.
The advancement of Internet of Things and associated technologies has led to the widespread usage of smart wearable devices, greatly boosting the demand for flexible antennas, which are critical electromagnetic components in such devices. Additive manufacturing technologies provide a feasible solution for the creation of wearable and flexible antennas. However, performance reliability under deformation and radiation safety near the human body are two issues that need to be solved for such antennas. Currently, there are few reports on compact, flexible ultrawideband (UWB) antennas with more notch numbers, reliable bendability, and radiation safety. In this paper, a UWB antenna with trinotched characteristics for wearable applications was proposed and developed using printable conductive silver materials consisting of silver microflakes or silver nanoparticles. The antenna has a compact size of 18 × 20 × 0.12 mm and adopts a gradient feeder and a radiation patch with three folding slots. It was fabricated on transparent and flexible poly(ethylene terephthalate) film substrates, using screen printing and inkjet printing. The measurement results demonstrated that the fabricated antennas could cover the UWB band (2.35-10.93 GHz) while efficiently filtering out interferences from the C-band downlink satellite system (3.43-4.21 GHz), wireless local area networks (4.66-5.29 GHz), and X-band uplink satellite system (6.73-8.02 GHz), which was consistent with the simulation results. The bendability and radiation safety of the antennas were evaluated, proving their feasibility for usage under bending conditions and near the human body. Additionally, it was found that the screen-printed antenna performed better after bending. The research is expected to provide guidance on designing flexible antennas that are both safe to wear and easily conformable.
物联网及相关技术的进步推动了智能可穿戴设备的广泛应用，极大地增加了对柔性天线的需求，柔性天线是此类设备中的关键电磁组件。增材制造技术为可穿戴和柔性天线的制造提供了一种可行的解决方案。然而，此类天线在变形情况下的性能可靠性以及靠近人体时的辐射安全性是需要解决的两个问题。目前，关于具有更多陷波数量、可靠可弯曲性和辐射安全性的紧凑型柔性超宽带（UWB）天线的报道较少。本文提出并开发了一种用于可穿戴应用的具有三陷波特性的UWB天线，该天线使用由银微片或银纳米颗粒组成的可印刷导电银材料制成。该天线尺寸紧凑，为18×20×0.12毫米，采用渐变馈线和带有三个折叠缝隙的辐射贴片。它是在透明且柔性的聚对苯二甲酸乙二酯薄膜基板上，采用丝网印刷和喷墨印刷工艺制造的。测量结果表明，所制造的天线能够覆盖UWB频段（2.35 - 10.93吉赫兹），同时有效滤除来自C波段下行卫星系统（3.43 - 4.21吉赫兹）、无线局域网（4.66 - 5.29吉赫兹）和X波段上行卫星系统（6.73 - 8.02吉赫兹）的干扰，这与仿真结果一致。对天线的可弯曲性和辐射安全性进行了评估，证明了它们在弯曲条件下和靠近人体时使用的可行性。此外，发现丝网印刷天线在弯曲后性能更好。该研究有望为设计既安全可穿戴又易于贴合身体的柔性天线提供指导。
