yang Li

All-dielectric metamaterial frequency selective surfaces based on high-permittivity ceramic resonators

In this letter, we propose the design of all-dielectric metamaterial frequency selective surface (FSS) using high-permittivity ceramics. The FSS is composed of 2D arrays of rectangular ceramic resonators. By adjusting the geometrical parameters of the ceramic resonator, the first two resonant modes are merged to achieve broadband band-stop property. As an example, a nearly 1.5 GHz wide stop-band is demonstrated both numerically and experimentally in X band. Since such FSSs are made of low-loss high-permittivity ceramics, they are of important values especially in high-temperature or high-power applications. The method can also be used to design all-dielectric FSS in other frequencies by simply scaling the geometry parameters.

A band enhanced metamaterial absorber based on E-shaped all-dielectric resonators

In this paper, we propose a band enhanced metamaterial absorber in microwave band, which is composed of high-permittivity E-shaped dielectric resonators and metallic ground plate. The E-shaped all-dielectric structure is made of high-temperature microwave ceramics with high permittivity and low loss. An absorption band with 1 GHz bandwidth for both TE and TM polarizations are observed. Moreover, the absorption property is stable under different incident angles. The band enhanced absorption is caused by different resonant modes which lie closely in the absorption band. Due to the enhanced localized electric/magnetic fields at the resonant frequencies, strong absorptions are produced. Our work provides a new method of designing high-temperature and high-power microwave absorbers with band enhanced absorption.

Reconfigurable all-dielectric metamaterial frequency selective surface based on high-permittivity ceramics.

Based on effective medium theory and dielectric resonator theory, we propose the design of reconfigurable all-dielectric metamaterial frequency selective surfaces (FSSs) using high-permittivity ceramics. The FSS is composed of ceramic resonators with different band stop responses under front and side incidences. By mechanically tuning the orientation of the ceramic resonators, reconfigurable electromagnetic (EM) responses between two adjacent stopbands can be achieved. The two broad stopbands originate from the first two resonant modes of the ceramic resonators. As an example, a reconfigurable FSS composed of cross-shaped ceramic resonators is demonstrated. Both numerical and experimental results show that the FSS can switch between two consecutive stopbands in 3.55–4.60 GHz and 4.54–4.94 GHz. The design method can be readily extended to the design of FSSs in other frequencies for high-power applications.

Achieving all-dielectric metamaterial band-pass frequency selective surface via high-permittivity ceramics

In this paper, we propose the design of all-dielectric metamaterial band-pass frequency selective surfaces (FSSs) using high-permittivity ceramics based on effective medium theory and dielectric resonator theory. The band-pass response can be determined by the permittivity of the dielectric material, the periodicity, and geometrical shape of the dielectric unit cell. As an example, a band-pass FSS composed of H shaped ceramic resonators is demonstrated. Both the simulation and experiment results show that the FSS can achieve a pass band in X-band. Since such FSSs are made of low-loss high-permittivity ceramics, they are of important application values, especially in high-temperature, high-power environments. The design method can be readily extended to the design of FSSs in other frequencies.

All-dielectric metamaterial frequency selective surface based on spatial arrangement ceramic resonators

In this paper, we demonstrate a method of designing all-dielectric metamaterial frequency selective surface (FSS) with ceramic resonators in spatial arrangement. Compared with the traditional way, spatial arrangement provides a flexible way to handle the permutation and combination of different ceramic resonators. With this method, the resonance response can be adjusted easily to achieve pass/stop band effects. As an example, a stop band spatial arrangement all-dielectric metamaterial FSS is designed. Its working band is in 11.65–12.23GHz. By adjusting permittivity and geometrical parameters of ceramic resonators, we can easily modulate the resonances, band pass or band stop characteristic, as well as the working band.

All-dielectric metamaterial frequency selective surface

Frequency selective surface (FSS) has been extensively studied due to its potential applications in radomes, antenna reflectors, high-impedance surfaces and absorbers. Recently, a new principle of designing FSS has been proposed and mainly studied in two levels. In the level of materials, dielectric materials instead of metallic patterns are capable of achieving more functional performance in FSS design. Moreover, FSSs made of dielectric materials can be used in different extreme environments, depending on their electrical, thermal or mechanical properties. In the level of design principle, the theory of metamaterial can be used to design FSS in a convenient and concise way. In this review paper, we provide a brief summary about the recent progress in all-dielectric metamaterial frequency selective surface (ADM-FSS). The basic principle of designing ADM-FSS is summarized. As significant tools, Mie theory and dielectric resonator (DR) theory are given which illustrate clearly how they are used in the FSS d...

All-dielectric metamaterial band stop frequency selective surface via high-permittivity ceramics

In this paper, a band stop all-dielectric metamaterial frequency selective surface (FSS) is designed based on effective medium theory and dielectric resonator theory. The FSS is made of high-permittivity ceramics without using any metallic parts. The stop band FSS is composed of 2D arrays of Jerusalem cross-shaped ceramic resonators. Solid-state sintering method is adopted to prepare the high-permittivity ceramics, which is made of 0.7Ba0.6Sr0.4TiO3-0.3La(Mg0.5Ti0.5)O3. The permittivity of this ceramics is about 110. The simulation results show that the FSS can achieve a stop band at 6.91-9.25 GHz. The relative effective permittivity, permeability and the normalized impedance of the structure are retrieved, showing that the first resonant is a magnetic resonant and the second resonant is an electric resonant. Due to the magnetic and electric resonant, the impedance matching becomes worse, so the normalized impedance is close to 0 and the stop band forms. The electric fields and magnetic fields of the resonant points are observed to further analysis the FSS. At the first resonant point, the electric field loop is formed, equivalent to a magnetic dipole. At the second resonant point, the magnetic field loop is formed, equivalent to an electric dipole. The magnetic and electric fields are accordance with the retrieved parameters. Since such FSSs are made of high-permittivity ceramics, they have potential engineering application in high-power or high-temperature.

Toward band-stop all-dielectric metamaterial frequency selective surface via dielectric ceramic blocks

In this paper, we design a band-stop all-dielectric metamaterial frequency selective surface (FSS) using dielectric ceramics. Four rectangular ceramic blocks, which possess high permittivity and low dielectric loss, can be spliced together to make the designed shapes. The design is based on effective medium theory and dielectric resonator theory. The band-stop response can be determined by the permittivity of the dielectric material, the periodicity and geometrical shape of the dielectric unit cell. The simulation results show that the FSS can achieve a stop band in 6.97-8.85GHz. Due to the utilizing of high-permittivity ceramics, this all-dielectric FSS have potential engineering application in high-temperature and high-power environments and also can be applied to other frequencies.

Polarization insensitive metamaterial absorber based on E-shaped all-dielectric structure

In this paper, we designed a metamaterial absorber performed in microwave frequency band. This absorber is composed of E-shaped dielectrics which are arranged along different directions. The E-shaped all-dielectric structure is made of microwave ceramics with high permittivity and low loss. Within about 1 GHz frequency band, more than 86% absorption efficiency was observed for this metamaterial absorber. This absorber is polarization insensitive and is stable for incident angles. It is figured out that the polarization insensitive absorption is caused by the nearly located varied resonant modes which are excited by the E-shaped all-dielectric resonators with the same size but in the different direction. The E-shaped dielectric absorber contains intensive resonant points. Our research work paves a way for designing all-dielectric absorber.

Frequency selective polarization conversion metasurface using E-shaped high permittivity ceramics

In this paper, a frequency selective polarization conversion metasurface is designed based on E-shaped high permittivity ceramics. A frequency selective polarization conversion is realized in 10.95GHz∼12.069GHz. Two magnetic resonances are generated, which lead to the cross-polarization reflection. The simulated results show that the maximum conversion efficiency is nearly 100% at the two resonant frequencies. In this paper, high permittivity ceramic material is used to design all-dielectric metasurface in microwave band. As an alternative method to design frequency selective polarization conversion metasurface, high permittivity ceramics provide potential applications in high temperature or high power.