To verify the design method, a reconfigurable FSS composed of cross-shaped resonators was designed, fabricated and measured. When the orientation of ceramic resonators is changed, the EM response of the FSS can be switched between two adjacent bands. Thus, the macroscopic electromagnetic properties of the proposed FSS can be described equivalently by effective permittivity and permeability. Due to the high-permittivity, the ceramic particles are sub-wavelength in size. In this paper, we proposed the design of reconfigurable all-dielectric metamaterial frequency selective surfaces (FSSs) using high-permittivity ceramics, without using any metallic parts. With this ability, an alternative method can be used to design tunable or reconfigurable FSS.
TOLERANT VERTICES CST MICROWAVE STUDIO HOW TO
The ability of changing these values at will is depending on how to inspire the desired resonant modes in the dielectric resonators. With this framework, the effective impedance of all-dielectric FSSs can be designed by tuning the effective relative permittivity and permeability. proposed all-dielectric metamaterial FSS at microwave frequencies based on high-permittivity ceramic resonators. In the framework of metamaterials, Li 34 et al. They pointed out that metamaterials fabricated with metallic inclusions possess conduction losses and anisotropy, which limit their electromagnetic properties. used dielectric resonators, instead of metallic patterns, to design all-dielectric metamaterials. These tunable FSSs are mostly based on liquid crystals and yet some of them still need metallic screens. With the development of all-dielectric FSSs, tunable FSS 26, 27, 28, 29, 30, 31 were further proposed and realized. also did impressive work in designing all-dielectric FSS at infrared or terahertz frequency using liquid crystal and single inhomogeneous dielectric layer. This shows that all-dielectric FSS have advantage over conventional metallic FSS under high power. The device was also tested in the passband at a high pulsed microwave with a power of 45.26 MW/m 2 and no damage was observed 22. In Barton’s work, all-dielectric FSS device was successfully tested at a peak power of 1.7 GW/m 2, indicating that all-dielectric FSS can operate normally under high power 21. designed an all-dielectric FSS based on guided-mode resonance for high-power applications at microwave frequencies 21 and they further developed a methodology for the design of all-dielectric FSS using fast Fourier transforms and genetic algorithm optimizations 22. designed many all-dielectric structures or filters based on guided-mode resonance effects in all-dielectric waveguide gratings at microwave frequencies and optical frequencies.
These works inspired researchers to develop all-dielectric periodic structures in filtering applications. used dielectric grating waveguide as filters. They found that at millimeter frequencies, dielectric layers have advantages over metallic screens in low absorption loss. studied frequency-selective reflection and transmission of a periodically modulated dielectric layer. The study of the application of dielectric materials in filters may date back to many decades ago.
Instead of metallic patches, high-permittivity ceramic particles are employed as the elementary unit cell to fabricate all-dielectric metamaterial FSSs. Therefore, it is imperative to develop new types of FSSs without using metallic structures. However, the metallic parts of the conventional FSSs are prone to breakdown, oxidization and corrosion, especially in high-power and high-temperature applications. Conventional FSS usually consists of a 2-D periodic array of slots/apertures etched out of a conducting plate or of conducting patches/strips printed on a dielectric substrate 1, 2, 3, 4. Due to this filtering property, FSS can be used in many applications. Frequency selective surface (FSS) is a kind of periodic structures that can be used to select incoming electromagnetic waves with different operating frequencies, polarizations and incident angles.