Analysis of a tunable frequency-selective surface on an in-plane biased ferrite substrate

Abstract

ishes. Again, the effect of the presence of a surface wave is apparent in the Figure. It has also been verified that the copolar component of the field coincides, in the limit p' -+ a/2, with the expressions obtained by the application of the standard Maliuzhinets method, valid at normal incidence. V. CONCLUSIONSA uniform high-frequency solution has been presented for three-dimensional diffraction at an edge in a planar anisotropic impedance surface. The solution applies to those cases where the anisotropic surface constitutes a face of either a half plane or a full plane, with the other face perfectly conducting. The particular kind of anisotropic impedance boundary condition adopted for the loaded face is characterized by a vanishing surface impedance in the direction perpendicular to the edge. It is suitable for modeling corrugated surfaces and strip-loaded grounded dielectric slabs, with the direction of either corrugations or strips normal to the edge. KEY TERMSFrequency-selectilje surface, bias fem'te substrate. tunable resonan/ frequency, Jerusalem cross, moment method ABSTRACT The response characteristic of a frequency-selectire surface (FSS) made up of a Jerusalem cross on a iri-plane biased fem'ie substrate is analyzed with the full-walre moment method. It is shown that the resonant frequent-v of a FSS cut1 be dynamically adjusted l>y changing the dc bias magnetic ,field. For nornial incidence of the plane electrotnagnetic wai'e, a resotlant-frequency s i l i~ of about 5 GHz can be obtained by tuning the bias dc magnetic field. It is furtherprorvd that it is easier tog~t the shifi of resonant frequency of a FSS fot the case of the Jerusalem cross than for the cross dipole for a girw range of bias magnetic field. For an oblique incidence of 45", about a 3-GHz resonant-frequency shift can be easily achieLmi. 0 I996 Johri Wiley & Sons, lnc. ABSTRACTWe describe the use of fiber-optic low coherence reflectometry to nonini'asiuely acquire three-dimensional images of Lysozyme protein cryftals in solution, with a 1-5-pm depth resolution. This &pe of noninc'asii'e protein ctystal growth monitoring might ultimately be used to impror>e the growth ptocesses in micrograr?ty environments. 0 I996 John Wley & Sons, Inc.

Fabrication of strain tunable infrared frequency selective surfaceson electrostrictive poly(vinylidene fluoride–trifluoroethylene) copolymer films using a stencil mask method

“…The resulting frequency selective surfaces exhibit resonance responses in the infrared region. 5 Tunable FSSs have potential applications in waveguide filters and reconfiguration reflector systems. The results demonstrate that the stencil mask method is useful for depositing metallic patterns on a subset of substrates such as polymers that would be damaged by solvents used in conventional photolithography techniques.…”

Thermally Tunable Frequency‐Selective Surface Based on VO2 Thin Film

“…[ 13 ] Optically tunable FSSs are based on photoconductive thin films. [ 14 ] Magnetically tunable FSSs are based on ferrite substrate [ 15 ] and tuned using an external magnetic field. Mechanical tuning can be implemented by applying stress and changing dimensions of the unit cells of the FSS [ 16 ] or using moving metal slugs that change an impedance of the unit cells.…”

Actuated Dielectric-Lossy Screen for Dynamically Suppressing Electromagnetic Interference

“…Numerous composite-based nonmagnetic metamaterials − and magnetic material-enabled metamaterials have been explored. − Due to the resonant nature of these metamaterials, however, they are inherently band limited. Tunable approaches have been explored to address this, for instance, through the use of external field-controlled shifts in ferromagnetic resonance (FMR); − however, this approach is intrinsically limited by the FMR response of the material systems utilized.…”