Flexible and diverse manipulation of electromagnetic (EM) waves in half space (reflection or transmission) has facilitated strong aspiration toward full-space wave control. However, it remains challenging to achieve independent amplitude and phase control, which seriously hinder the real-world applications. Herein, an innovative strategy of trifunctional metasurface is proposed to independently and simultaneously manipulate the amplitude and phase of circular polarized waves in full space. The multifunctional design is composed of double-layer anisotropic metasurface sandwiched with a bandpass frequency selective surface, with a frequency-direction multiplexed paradigm for on-demand control of both amplitude and phase across three independent channels. To validate the concept, a multifunctional metadevice is designed and verified by simulations and experiments, showcasing arbitrary near-field and far-field power modulation in full space. Lateral and axial bifocal metalenses with desired intensity distribution are designed in two reflection channels at 9 GHz, while multibeam generator with desired spatial scatterings and power allocations is designed in transmissive channel at 13 GHz. The finding paves the way for attaining multifunctional metadevices with amplitude and phase modulation in full space, which have potential applications in high-quality imaging and high-capacity communication systems.

中文翻译：

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全空间三功能超表面，可独立控制圆极化波的振幅和相位


在半空间（反射或传输）中灵活多样地操纵电磁 （EM） 波，促进了对全空间波控制的强烈渴望。然而，实现独立的幅度和相位控制仍然具有挑战性，这严重阻碍了实际应用。在此，提出了一种创新的三功能超表面策略，以独立和同时操纵全空间圆极化波的振幅和相位。多功能设计由夹在带通频率选择表面的双层各向异性超表面组成，具有频率方向多路复用范式，用于跨三个独立通道按需控制振幅和相位。为了验证这一概念，设计了一个多功能超器件，并通过仿真和实验进行了验证，展示了全空间下的任意近场和远场功率调制。具有所需强度分布的横向和轴向双焦点超透镜设计在 9 GHz 的两个反射通道中，而具有所需空间散射和功率分配的多光束发生器设计在 13 GHz 的透射通道中。这一发现为实现全空间幅度和相位调制的多功能超器件铺平了道路，这在高质量成像和大容量通信系统中具有潜在的应用价值。