Ferroelectric thin-film based two-dimensional electromagnetic structures
Integrated Ferroelectrics: An International Journal
A two-dimensional electromagnetic bandgap structure has been developed using ferroelectric thin-films. Using lumped inductors and parallel plate capacitors a planar structure is developed which creates a bandgap in the 20–40 GHz range, as demonstrated by experimental results. The ferroelectric material Ba0.6Sr0.4TiO3 (BST) is used in the form of a thin-film between patterned layers of gold to form capacitors on a 500 μm thick high-resistivity Si substrate. A meander line based design is used to form the two-dimensional surface which provides biasing pathways to the varactors. The concept is simulated and experimentally verified using a coplanar waveguide based device in which the EBG surface is used as the ground plane. Designs are also presented for the development of a biasing network to take advantage of the non-linear tunability of the BST dielectric constant in order to make the surface tunable. Experiments used both sputtered and PLD BST films with a maximum bandgap depth of 35 dB. Potential applications are in the area of frequency selective surfaces, and high-impedance ground planes.
Taylor & Francis Group
Tunable microwave dielectrics, ferroelectric thin-film, varactors, electromagnetic bandgap, frequency selective surface, high-impedance surface
Khan, U.; Subramanyam, Guru; Gevorgian, S.; and Vorobiev, A., "Ferroelectric thin-film based two-dimensional electromagnetic structures" (2007). Electrical and Computer Engineering Faculty Publications. 38.