The ever-increasing demand for high-datarate wireless systems has led to a crowded electromagnetic (EM) spectrum. This demand has successively spurred the development of versatile microwave and millimeter-wave integrated components possessing high selectivity, multifunctionalities, and enhanced efficiency. These components require a class of nonreciprocal structures endowed with extra functionalities, e.g., frequency generation, wave amplification, and full-duplex communication. Space-time (ST) modulation has been shown to be a perfect candidate for high-data-rate transmission given its extraordinary capability for EM-wave engineering. ST-modulated (STM) media are dynamic, directional EM structures whose constitutive parameters vary in both space and time.

中文翻译：

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时空调制：原理和应用

对高数据速率无线系统不断增长的需求导致了拥挤的电磁 (EM) 频谱。这种需求相继推动了具有高选择性、多功能性和更高效率的通用微波和毫米波集成组件的开发。这些组件需要一类具有额外功能的非互易结构，例如频率生成、波放大和全双工通信。鉴于空时 (ST) 调制在电磁波工程方面的非凡能力，它已被证明是高数据速率传输的完美候选者。ST 调制 (STM) 媒体是动态的、定向的 EM 结构，其本构参数在空间和时间上都不同。