Title

Ferroelectric thin-film based two-dimensional electromagnetic structures

Document Type

Article

Publication Date

1-2007

Publication Source

Integrated Ferroelectrics: An International Journal

Abstract

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.

Inclusive pages

67-76

ISBN/ISSN

1058-4587

Publisher

Taylor & Francis Group

Volume

86

Issue

1

Peer Reviewed

yes

Keywords

Tunable microwave dielectrics, ferroelectric thin-film, varactors, electromagnetic bandgap, frequency selective surface, high-impedance surface