Memristors for Low-Power, Passive RF Devices

摘要智力价值：自适应阻抗匹配使得能够开发具有动态波束成形能力的低成本混合天线，这将改善无线通信的性能。然而，现有方法存在若干挑战，包括：（i）混合天线中的固定阻抗限制了灵活性并阻止了动态波束成形，（ii）用于阻抗切换的半导体的使用具有若干缺点。这些问题包括：（a）要求？持有？通过维持最小激活电压使晶体管处于特定状态，导致其能量消耗增加，以及（B）晶体管和半导体的非线性引入偏置，其改变天线接收的强信号和弱信号之间的有效阻抗。相比之下，本项目的目标是研究和设计一种新的方法，以射频前端设计与忆阻器取代传统的CMOS阻抗开关。特别是，基于忆阻器的RF前端将用于无源RFID技术和混合天线设计。预期的贡献包括了解忆阻器在射频（RF）应用中的性能，以及更灵活的天线阻抗匹配网络设计。这项工作的最终结果可能会导致天线和射频前端设备设计的变革性范例。更广泛的影响：主要的提案成果是对不同类型的忆阻器如何应用于射频系统的新知识和理解，例如用于弱信号的自适应天线阵列，以及阻抗匹配网络及其调谐的简化设计。这将使无源射频识别（RFID）系统中更便宜和更简单的波束成形混合天线的新设计成为可能。这些好处将适用于其他通信系统，如认知网络和雷达系统。一套推广活动包括通过密苏里州ST学生多样性方案办公室和K-12外展，通过密苏里州ST夏季研究学院（SRA）方案吸引高中生参与，让妇女和少数民族学生参与。从长远来看，这些成果将支持许多基于忆阻器的技术在通信系统中的应用，包括可穿戴天线系统和传感器，并提高农村地区无线互联网接入系统的性能和覆盖范围。

AbstractIntellectual Merit: Adaptive impedance matching enables development of low cost hybrid antennas with dynamic beamforming capabilities that will improve the performance of wireless communication. However, there are several challenges with existing approaches including: (i) fixed impedance in hybrid antennas restricts flexibility and prevents dynamic beamforming, (ii) employment of semiconductors for impedance switching has several drawbacks. These include: (a) requirement of ?holding? a transistor in a specific state by maintaining a minimum activation voltage leading to an increase in its energy consumption, and (b) nonlinearity of transistors and semiconductors introduce a bias, which changes the effective impedance between strong and weak signals received by an antenna. In contrast, the goal of this project is to study and design a novel approach to RF front-end design with memristors replacing traditional CMOS-based impedance switching. In particular, the memristor-based RF front ends will be employed in a passive RFID technology and hybrid antenna design. The expected contributions include understanding the performance of memristors in radio frequency (RF) applications, and more flexible design of impedance matching networks for antennas. The end result of this effort could lead to a transformative paradigm in designing antennas and RF front-end devices.Broader Impact: The main proposal outcomes are a new knowledge and understanding of how different type of memristors could be applied to RF systems such as adaptive antenna arrays for weak signals, and a simplified design of impedance matching networks and their tuning. This will enable new designs of cheaper and simpler beamforming hybrid antennas in passive radio frequency identification (RFID) systems. The benefits will apply to other communication systems such as cognitive networks and radar systems. A set of outreach activities include engagement of women and students from under-represented minorities through the Missouri S&T Student Diversity Programs office and K-12 outreach that engages high school students through the Missouri S&T Summer Research Academy (SRA) program. In the long term, the outcomes will support a number of memristor based technology applications in communication systems including wearable antenna systems and sensors, and enhancing performance and coverage of wireless Internet access systems for rural, currently-not-serviced areas.