基于多层结构的人工表面等离激元集成与调控研究

Spoof Surface Plasmon Polariton (Spoof SPP)-based transmission lines (TLs), which possess sub-wavelength field confinement, low bending loss and conformal propagation with the curvature of the surface, exhibit promising advantage in ultra-compact microwave and millimeter integrated circuits. Passive and active devices based on Spoof SPPs have been realized experimentally, such as filters, power splitters, amplifiers and phase-shifters. As there’s no need for large-area ground plane and the propagation constants can be real-time tuned by the loaded varactor, Spoof SPP-based TLs may have more advantages in multilayer integrated and dynamically-controlled circuit module. This project will focus on the integration and dynamic control of Spoof SPPs based on multilayer circuit structures. Firstly, we will investigate the mechanisms of inter-layer coupling and decoupling in multilayer Spoof SPPs, and design structures to realize wideband and low-loss inter-layer transition, and structures for high isolation between independently transmitting Spoof SPP signals in different layers. Secondly, we will try to achieve the isolation between the microwave network of Spoof SPPs and the bias-circuit of active devices, possibly via circuit topology model and impedance transformation. At last, we will realize multilayer integration and dynamic control of Spoof SPPs functional modules, and try to optimize the arrangement of wires and make the modules more compacted. All these researches will provide technical supports for Spoof SPP-based integrated circuits and communication systems, and also promote the development and reformation of microwave integrated circuits.

人工表面等离激元传输线具有亚波长的场局域性、低弯曲损耗、可共形传输等特性，符合微波毫米波电路集成化和小型化趋势，已发展出滤波器、功分器、放大器、混频器等无源和有源器件。人工表面等离激元传输线无需大面积地层，其传输特性可由加载的二极管实时调控，因此发展基于多层结构的人工表面等离激元集成和调控，有望实现更高的集成度和更灵活的功能。本项目围绕基于多层结构的人工表面等离激元集成及调控开展创新性研究：1.揭示人工表面等离激元层间信号的耦合/去耦机制，实现宽频谱、低损耗的层间过渡，以及对相邻层间信号串扰的抑制；2.研究人工表面等离激元信号与有源器件的直流偏置电路间的去耦方法；3.在多层人工表面等离激元电路中进行器件的功能集成和动态调控，实现高度集成和高性能的功能模块。本项目的研究成果将为人工表面等离激元集成电路和通信系统提供关键的技术储备，并推动微波毫米波集成电路技术的发展和革新。

人工表面等离激元，利用亚波长周期性金属结构，在微波和太赫兹频段复现光频表面等离激元模式，具有深度亚波长场束缚性、近场电场增强等特性，在微波集成电路领域得到了广泛的关注和研究。基于多层人工表面等离激元灵活的结构，以及有源器件加载的动态调控，对实现高性能高集成度的微波电路及系统具有重要意义。在三年的研究过程中，项目团队完成了计划的研究任务，并拓展了研究范围，主要研究内容和成果包括：1.探索了不同的多层结构形式，分析其中模式特性、耦合机理，并进行高性能器件设计；2.提出了多种有源器件加载方式，研究其中微波信号和直流偏置电路间的耦合去耦，在此基础上实现多种功能的器件和电路调控；3.进行了人工表面等离激元无线通信系统搭建，并实现超越微带系统的优异性能；4.拓展研究了不同结构的人工表面等离激元谐振，并探索多种传感机理，实现了高度集成化小型化和高灵敏度的微波传感器。本项目研究成果补充和完善了人工表面等离激元的理论体系，并在微波集成电路、微波系统、微波传感等领域展现了可观的应用前景。