EAGER: SARE: Multiferroic Shields for Smart Analog Security

多铁性材料允许通过主动偏置来控制介电和磁性能。利用这些特点，该项目将引入新型的适应性和可重构电磁结构。具体来说，该项目将开发多铁衬底、可调谐偏置网络和电磁结构，用于通用平台上的封装和集成。研究还将集中于合成与这种集成兼容的多铁衬底。目标是实现本体基板特性的主动控制和可重构性，以提供无线通信系统的自适应射频屏蔽。总体而言，该项目旨在通过减少无线干扰来提高射频系统的安全性，同时允许安全的数据通道。重点将是实现无线电波的选择性阻断或传输，以及频率和发射方向的可重构性。这个多学科项目将在广泛应用的多铁学和电磁学领域之间架起桥梁。该项目利用佛罗里达国际大学的两个活跃的NSF本科生研究经验（REU）站点来改善本科生的外展和培训。具体来说，该项目将引入新的架构和外部磁场偏置来控制大块基板的介电特性。材料集成将用于可调谐反射天线阵列、发射天线阵列、频率选择表面（FSS）和天线，从而利用多铁基板的特性实现可调谐。该项目有三个主要的研究组成部分：(1)通过嵌入由钴铁氧体核和钛酸锶钡（BST）壳形成的核壳纳米颗粒合成多铁性衬底；(2)集成频率选择表面和天线结构，与可调谐多铁质衬底共同设计用于动态通带；(3)发展有源偏置网络，以控制多铁性介质特性，同时对FSS和天线性能保持中立。除此之外，该项目还将专注于降低有源网络的功率水平，以提高效率。这将通过使用纳米磁场放大剂和多铁性纳米复合材料来实现。研究还将侧重于有效封装偏置结构、电磁结构和多铁质衬底，以实现3D激励和调谐。这些解决方案将在可调谐屏蔽应用中进行实验验证，随后在无线通信系统中进行测试，以验证项目成果。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。

Multiferroic materials allow for dielectric and magnetic property control through active biasing. Leveraging these features, this project will introduce new types of adaptable and reconfigurable electromagnetic structures. Specifically, the project will develop multiferroic substrates, tunable biasing networks, and electromagnetic structures for packaging and integration on a common platform. Research will also focus on synthesis of multiferroic substrates compatible for such integration. The goal is to attain active control and reconfigurability of bulk substrate properties to provide an adaptable RF shielding of wireless communication systems. Overall, the project aims to increase security to RF systems through mitigation of wireless interferences, concurrently allowing secure data-channels. Focus will be on achieving selective blocking or transmission of radio waves, and reconfigurability of frequency and transmitting direction. This multidisciplinary project will bridge the gap between broadly applicable fields of multiferroics and electromagnetics. The project leverages two active NSF Research Experience for Undergraduates (REU) sites at Florida International University to improve outreach and training of undergraduates.Specifically, the project will introduce new architectures and external magnetic-field biasing to control the dielectric properties of bulk substrates. Material integration will be pursued for tunable reflecting antenna arrays, transmitting antenna arrays, frequency selective surfaces (FSS) and antennas and thus exploit the properties of multiferroic substrates towards tunability. The project has three broad research components: (1) synthesis of multiferroic substrates by embedding core-shell nanoparticles formed by cobalt ferrite cores and barium strontium titanate (BST) shells; (2) integration of frequency selective surfaces and antenna structures, co-designed with tunable multiferroic substrates for dynamic passbands; (3) development of active biasing networks to control multiferroic media properties while concurrently being neutral to the FSS and antenna performance. Beyond these, the project will focus on reducing power levels of active networks for efficient performances. This will be achieved by using nanomagnetic field amplifying agents and multiferroic nanocomposites. Research will also focus on effective packaging of the biasing architectures, electromagnetic structures and multiferroic substrates to achieve 3D excitation and tuning. These solutions will be experimentally demonstrated for tunable shielding applications and subsequently tested with wireless communication systems to demonstrate the project outcomes.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.