SpecEES: Tag-of-Everything: Secured Wireless Powering and Communication Using THz Spectrum for Ultra-Small, Package-Less ID Chips

使用射频识别（RFID）的标签在整个商业产品供应链中得到越来越多的采用。目前用于射频识别的兆赫兹（MHz）和千兆赫兹（GHz）频段将很快变得拥挤，特别是考虑到许多协同定位的射频识别设备同时询问的干扰以及分配给射频识别的有限带宽。此外，目前的RFID设备受限于其用于无线供电和数据传输的片外组件，其封装成本相对较高，外形尺寸较大。低可用功率也阻碍了在RFID设备上使用高安全性算法和硬件。这些问题阻碍了该技术在药品、半导体芯片、纸币等认证领域的有效性和应用。本项目将应用低太赫兹（~0.3太赫兹）无线供电和反向散射电路技术，为未来的RFID标签探索新的电磁频谱。1000倍大的带宽和高度准直的下行和上行波束将容纳比我们今天更多的数量级标签。在半导体芯片上实现的新型太赫兹RFID设备还将具有无封装的超小型形式，从而大幅降低成本并具有广泛的应用范围。该提案还将为拟议的太赫兹射频识别芯片开发节能认证硬件和算法，以确保与金融和生物识别信息相关的敏感数据的存储和传输。拟议的研究将与一些外展活动紧密结合，包括SuperUROP本科生研究计划、“标记世界”系列讲座、麻省理工学院暑期研究计划（MSRP）的实习、麻省理工学院新星职业研讨会，以及K-12学生的一些“T-Ray实验室日”活动。该项目将利用定制设计的超高速肖特基势垒二极管进行实际太赫兹功率整流，预计太赫兹到直流的转换效率高达50%。与二极管共同设计的新型天线阵列采用多功能电磁学方法，可同时进行大孔径无线供电和基于后向散射的数据通信。此外，系统还将采用低能耗认证协议和硬件。特别是，该RFID芯片将配备一个抗侧信道的椭圆曲线处理器，该处理器使用动态电压频率缩放（DVFS）将其直流功率降低到微瓦水平。该芯片还将实现用于密钥存储的新型cmos兼容存储器，以及用于防窃听的RFID标签输出波的波束控制。这种无封装、无电池的RFID芯片预计体积小于十分之一立方毫米。最后，使用高速磷化铟（InP）异质结双极晶体管（hbt），该项目将创新一个太赫兹询问器收发器，与RFID芯片配对。凭借可扩展的阵列架构和高通用性的收发器前端电路单元，询问器将能够以高度聚焦的光束辐射超过100兆瓦的功率。该方法将提高电磁频谱的利用效率和多样性，为安全无线数据认证提供端到端解决方案。该项目还将为高频和高安全性集成电路提供新的设计方法，特别是在功率受限的条件下。该奖项反映了美国国家科学基金会的法定使命，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。

Tagging using radio-frequency identification (RFID) is getting increasing adoption throughout the supply chains of commercial products. The megahertz (MHz) and gigahertz (GHz) bands currently used for RFID will soon become congested, especially considering the interference from simultaneous interrogations of many co-located RFID devices and the limited bandwidth allocated for RFID. In addition, limited by their off-chip components for wireless powering and data transmission, current RFID devices have relatively high packaging cost and large form factor. The low available power also prevents the usage of high-security algorithms and hardware on the RFID devices. All these problems have hindered the effectiveness and application of the technology in areas like authentications of medicines, semiconductor chips, banknotes, etc. This project will apply low-terahertz (~0.3 THz in this project) wireless powering and back-scattering circuit techniques to explore a new electromagnetic spectrum for future RFID tagging. The 1000 times larger bandwidth and the highly-collimated downlink and uplink beams will accommodate orders of magnitude more tags than what we have today. The new THz RFID device realized on a semiconductor chip will also have a package-less ultra-small form, leading to dramatic cost reduction and wide range of applications. The proposal will also develop energy-efficient authentication hardware and algorithms for the proposed THz RFID chip to secure the storage and transmission of sensitive data related to, for example, financial and biometric information. The proposed research will be tightly integrated with a few outreach activities, including a SuperUROP undergraduate research program, a "Tagging the World" lecture series, an internship through MIT Summer Research Program (MSRP), a career workshop at MIT Rising Star, and a few "T-Ray Lab Day" events for K-12 students.This project will utilize custom-designed, ultra-high-speed Schottky-barrier diodes to perform practical THz power rectification, with an expected THz-to-DC conversion efficiency of up to 50%. A novel antenna array, which is co-designed with the diode and adopts a multi-functional electromagnetics methodology, will also be developed to simultaneously perform large-aperture wireless powering and back-scattering-based data communication. In addition, low-energy authentication protocols and hardware will be applied to the system. In particular, the RFID chip will be equipped with a side-channel resistant elliptic curve processor, which uses dynamic voltage-frequency scaling (DVFS) to reduce its DC power to microwatt level. Novel CMOS-compatible memory for secret-key storage, as well as beam-steering of the RFID tag output wave for anti-eavesdropping, will also be implemented in the chip. The package-less and battery-less RFID chip is expected to have a volume smaller than one tenth of a cubic millimeter. Lastly, using high-speed indium phosphide (InP) heterojunction bipolar transistors (HBTs), the project will innovate a THz interrogator transceiver to pair with the RFID chips. With a scalable array architecture and high-versatility transceiver front-end circuit units, the interrogator will be able to radiate more than 100 mW of power with highly focused beam. The proposed approach will advance the utilization efficiency and diversity of electromagnetic spectrum, as well as the end-to-end solutions for secured wireless data authentication. The project will also generate new design methodologies for both high-frequency and high-security integrated circuits, especially under power-constrained conditions.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.