Millimeter wave antennas have applications in several sensing and communication systems. Such antennas, designed for modern miniaturized devices and systems, must be low profile, flexible, and low cost. Some applications also require beam steering for detection purposes. Combining all these features into an antenna system and delivering decent antenna performance is challenging. In this study, we combined a partially reflective surface with a parasitic patch array to create a simple beam-switching, low-profile, and flexible wearable detection system. To ensure lower costs as well as compatibility with wearable systems, screen printing was utilized on a flexible substrate. The antenna array was optimized for the 77 GHz band and had a high gain of 11.2 dBi. The designed system has three independent beams, which can be oriented from bore-sight to ±32° through a simple switching mechanism. The antenna array maintains its performance in both flat and flexed conditions. Finally, the antenna array was tested in the field to successfully detect objects moving in three different directions.

中文翻译：

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适用于可穿戴应用的丝网印刷，柔性，寄生波束转换毫米波天线阵列

毫米波天线已在多种传感和通信系统中得到应用。设计用于现代小型设备和系统的这种天线必须是薄型，柔性和低成本的。一些应用还需要光束转向以进行检测。将所有这些功能组合到天线系统中并提供良好的天线性能是一项挑战。在这项研究中，我们将部分反射的表面与寄生贴片阵列相结合，创建了一个简单的光束切换，低调且灵活的可穿戴检测系统。为了确保较低的成本以及与可穿戴系统的兼容性，在柔性基板上使用了丝网印刷。天线阵列针对77 GHz频段进行了优化，并具有11.2 dBi的高增益。设计的系统具有三个独立的光束，通过一个简单的开关装置，它就可以从视线到±32°定向。天线阵列在平坦和弯曲条件下均能保持其性能。最终，在现场对天线阵列进行了测试，以成功检测沿三个不同方向移动的物体。