High Performance Optically-Controlled RF Switches with Ferroelectric Latching for Advanced Reconfigurable mmW-THz Circuits

该项目将研究和开发一种新型的毫米波到太赫兹（mmW-THz）宽带RF开关技术，该技术利用光波控制和铁电材料的独特性能来提供上级性能。该项目产生的开关将能够开发下一代mmW-THz传感，成像和通信系统所需的新型更先进的可调谐或可重新配置电路和组件。这是一个重要的技术领域，具有广泛的应用，将为社会带来巨大的利益。例如，基于开关的可重新配置mmW-THz滤波器可以实现用于物质或材料识别和检测的光谱感测和成像、先进的化学和生物感测、疾病或癌症诊断以及国防和安全筛查。此外，采用基于开关的波束转向或波束成形相控阵天线系统和可调谐滤波器的自适应mmW-THz通信网络可能对未来6 G或更高级别的蜂窝网络、物联网、芯片到芯片超高速互连、4K电视信号广播、多媒体下载以及安全的军事和国防通信链路产生深远影响。该项目还为学生提供了重要的教育机会。从事该项目的研究生将沉浸在跨学科的研究中，包括半导体物理，电磁波传播，先进的THz系统设计和表征，从单个器件到电路和系统级别。本科生，包括那些来自代表性不足的群体，将通过夏季研究计划或荣誉论文研究参与，并由主要研究人员指导。最后，该项目还将通过NSF教师研究经验（RET）计划，通过实验室图尔斯参观和实践STEM活动，促进当地中学和高中的科学和工程教育。 该项目的目标是开发和演示一种基于半导体中自由载流子光调制的新型mmW-THz宽带开关技术（例如，硅、锗等）使用新颖的器件和电路结构来提供上级开关性能和增强的功能。mmW-THz器件设计与半导体中光致载流子的光学控制的结合，包括使用非接触电容耦合结构来增强载流子调制，对于器件性能的进步超过当前技术水平是至关重要的。此外，使用铁电材料铪锆氧化物（HZO）的开关/锁存将被集成到光学调制开关中，提供了非易失性mmW-THz开关状态保持以及低功耗的首次演示。此外，新的开关可以利用计算机编程的光模式进行空间光调制，使其适用于大规模阵列应用。这项研究将导致光控宽带mmW-THz开关，紧凑，低功耗，易于制造和集成到电路和系统中，同时提供上级性能优于传统的半导体开关，新兴的相变材料（PCM）的同行，和一些微机电系统（MEMS）开关。新开关将用于实验演示mmW-THz可调谐和可重构原型，包括基于波导平台的可重构滤波器和基于开关的波束转向或波束成形天线。通过使用该项目开发的RF开关技术，可以实现下一代传感、成像和通信系统所需的更先进的可调谐或可重构mmW-THz电路和组件。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The project will investigate and develop a novel millimeter-wave to terahertz (mmW-THz) wideband RF switching technology using lightwave control and the unique properties of ferroelectric materials to deliver superior performance. The switches resulting from this project will enable the development of a novel class of more advanced tunable or reconfigurable circuits and components required in the next generation mmW-THz sensing, imaging and communication systems. This is an important technological area with a wide range of applications that will generate significant benefits to society. For example, switch-based reconfigurable mmW-THz filters may enable spectroscopic sensing and imaging for substance or material identification and detection, advanced chemical and biological sensing, disease or cancer diagnostics, and defense and security screening. In addition, adaptive mmW-THz communication networks employing switch-based beam-steering or beam-forming phased-array antenna systems and tunable filters may have profound impact on future 6G or beyond cellular networks, the internet-of-things, chip-to-chip ultra-high-speed interconnections, 4K TV signal broadcasting, multimeda downloading, and secure military and defense communication links. The project also provides significant educational opportunities for students. The graduate students working on this project will be immersed in an interdisciplinary research including semiconductor physics, electromagnetic wave propagation, advanced THz system design and characterization from single device to circuit and system levels. Undergraduate students, including those from underrepresented groups, will be involved through summer research program or honors thesis research and mentored by the principal investigators. Finally, this project will also promote science and engineering education among local middle schools and high schools through NSF Research Experience for Teachers (RET) program with lab tours and hands-on STEM activities. The objective of this project is to develop and demonstrate a novel mmW-THz wideband switching technology based on optical-modulation of free carriers in semiconductors (e.g., silicon, germanium, etc.) using novel device and circuit architectures to deliver superior switching performance and enhanced functionality. The combination of mmW-THz device design with optical control of photo-induced carriers in semiconductors, including the use of non-contact capacitively coupled structures to enhance carrier modulation, is central to the advancement of device performance beyond the current state of the art. In addition, switching/latching using ferroelectric material hafnium zirconium oxide (HZO) will be integrated into the optically modulated switches, providing the first demonstration of non-volatile mmW-THz switch state retention as well as low power consumption. Furthermore, the new switches can exploit spatial optical modulation using computer-programmed light patterns, making them suitable for large-scale array applications. This research will lead to optically controlled wideband mmW-THz switches that are compact, offer low power consumption, and are easy to fabricate and integrate into circuits and systems, while simultaneously providing performance superior to conventional semiconductor switches, emerging phase-change material (PCM) counterparts, and some micro-electromechanical system (MEMS) switches. The new switches will be employed to experimentally demonstrate mmW-THz tunable and reconfigurable prototypes including reconfigurable filters based on waveguide platforms and switch-based beam-steering or beam-forming antennas. By using the RF switching technology developed in this project, more advanced tunable or reconfigurable mmW-THz circuits and components required in the next generation sensing, imaging and communication systems can be realized.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.