A Frequency Selective Surface Design Fabricated with Tunable RF Meta-Atoms

Abstract

Frequency selective surfaces are being used in applications from RF to optical systems. Current applications involve beam steering or blocking transmission for electromagnetic signals. The RF Meta-atom is an excellent and novel component for frequency selective surfaces which alter or block propagating RF signals. Based on research into the tunable RF meta-atoms, a frequency selective surface has been developed that effects the propagation of RF signals. Integrating RF meta-atoms with microelectromechanical systems varactors provides a tunable method for frequency selective surfaces. Optimization of the frequency selective surface is performed through design, modeling, simulation and experimental testing for controlling propagating electromagnetic signals. To test the design concept, an RF meta-atom array was fabricated using surface micromachining fabrication methods. The RF meta-atom array was placed into RF strip-line to experimentally show the transmission and reflection response of propagating electromagnetic signals impending onto the array. The experimental results show that the resonant null at 4.85 GHz decreases from a transmission magnitude of 0.51 at 0 VDC to 0.14 at 70 VDC. This investigation shows results on how RF meta-atoms integrated with MEMS varactors can be arrayed for frequency selective surfaces.