Intellectual Merit: The objective of this research is to develop new radio-frequency front-end systems, filters, transmission lines, and antenna array topologies with multi-reconfigurable characteristics through the unique properties of phase-change materials. The defined research tasks span from fundamental materials science to system integration, creating an intersection that leads to a new path in the design of reconfigurable radio-frequency front-ends and antenna arrays. The components that will be developed are expected to have a wide range of responses. These responses will be enabled by the following approaches: (1) the changes in the electric properties of vanadium dioxide across its phase transition, (2) the compatibility with other components of different characteristic impedance due to the controlled impedance matching and bandwidth through the variable resistivity and dielectric permittivity, and (3) multiple frequencies with "analog" tuning as well as patterns and polarizations. Vanadium dioxide is a multifunctional phase change material (i.e. a smart material) that will be integrated in specific radio-frequency designs in the form of patterned thin films. The drastic and abrupt continuous variability in the dielectric permittivity and resistivity of patterned vanadium dioxide films across their phase change will be used as the reconfiguring element, while their hysteretic behavior will be used to program multiple states in the devices. The reconfigurability and programmability of the proposed devices will be characterized in terms of amplitude and phase response.
Broader Impact: The integration of multifunctional phase change materials in antenna and microwave component designs adds a new degree of freedom for radio-frequency component engineers. The proposed research will produce multi-reconfigurable antenna arrays and will benefit applications including array miniaturization, feed networks, and composite transmission lines. The educational and outreach plan spans from elementary school through the doctorate level and involves scientific presentations at conferences, journal publications, social media, course enrichment, an open-source software development, and the promotion of a multidisciplinary learning experience through the exchange of complementary knowledge between the two institutions.
