Reconfigurable passive RF circuits leveraging integrated fluidic structures

Abstract

The demand for wireless capability in our everyday life is continually increasing. This demand is creating the need for multi-band systems and systems that can be changed to adapt to their environment. Many research groups are looking into ways to meet these needs. One area in particular, is incorporation of fluidics in RF design to change the circuit's characteristics by leveraging conductive, magnetic, or dielectric properties of the fluid. The work presented focuses on leveraging the dielectric properties of fluids and how fluids may be integrated into fundamental RF structures providing control over their characteristics. Ultimately, providing design concepts that could be refined for particular applications.Fluids are integrated into four fundamental structures in this work: 1) a transmission line, 2) a directional coupler, 3) an annular slot antenna, and 4) a band-pass filter. The transmission line focuses on the use of the dielectric properties of fluids to create a tunable delay line. The directional coupler work demonstrates how fluids can be used to vary coupling and isolation in a microstrip structure. Fluids are next integrated into antenna structures demonstrating the possible tuning range. Lastly, a fluidic channel is integrated into a microstrip ring band-pass filter demonstrating the change in pass-band characteristics.