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This paper presents finite difference time domain (FDTD) method for property analysis of waveguide loaded artificial circular dielectric resonator with anisotropic permittivity. The property of artificial circular dielectric resonator emphasized on the analysis is the resonant frequency of some resonance mode which is affected by its anisotropic permittivity. The FDTD method used for the analysis...
A high efficiency broadband reflective polarization converter based on metamaterial is proposed, analyzed and measured. The substrate is FR4 with thickness of 3mm and the period is 8 mm. Simulated results show that the polarization conversion ratio is above 90% from 9.50 GHz to 15.41 GHz and it's above 99% at frequencies 10.43 ∼ 12.38 GHz and 13.90 ∼ 14.77 GHz. In order to fabricate the converter...
A tri-band ultra-thin absorber using frequency selective surface (FSS) structure is proposed and experimentally measured in this paper. The simulated results show that three distinct absorption peaks centre at 3.42 GHz (S-band), 6.34 GHz (C-band) and 9.01 GHz (X-band) with absorptivities of 95.1%, 91.7% and 91.9%, respectively. Thus, the proposed structure has ultra-thin thickness of 0.8mm and miniaturized...
A novel minimized microstrip planar antenna with pre-controllable resonant frequency and impedance matching is presented for microwave engineering applications. Double-sided planar structure is adopted to build the resonant loop of the antenna. The tuning of the impedance matching and the resonant frequency is studied, and the impedance matching and resonant frequency can be adjusted independently...
A new low profile ultra-wideband (UWB) monopole-type antenna is present in this paper. It is top-loaded with the metal plate to reduce its height. The feed point is located at the bottom of cylinder. Three shorting stubs on the edge and the central metallic circular truncated cone connected to the ground are used to further reduce the size of the antenna. The antenna has a 56% relative bandwidth covering...
In this paper, the artificial dielectric material with anisotropic permittivity is proposed to lower the resonant frequency of square patch antenna. The anisotropic artificial dielectric material is applied to replace the dielectric material usually used for implementing the conventional square patch antenna. Here, the conventional square patch antenna which is designed based on TM10 resonance mode...
In this paper, a novel microstrip antenna using interdigital capacitor is proposed. The DGS technology is used to further reduce the size of the antenna. The size of the improved antenna is 24% of traditional rectangular microstrip antenna, and the antenna has frequency range 2.4–2.52 GHz with maximum gain of 2.35 dB, meet the requirement for ISM band applications, realize the miniaturization design.
In space plasma, the determination of the electron density is an important parameter to understand the wave propagation and energy transfers between wave and particles. Usually, the plasma density and debye length are much different in solar wind and planetary environment than laboratory plasma and it is needed to sound large volume. Several ways exist to estimate the electron density that can separate...
We describe experimental characterization of switchable terahertz metasurfaces using broadband ellipsometry. A theoretical framework based on generalized sheet transition conditions is developed to extract surface susceptibility as a function of frequency and applied DC bias. This will allow us to make a priori predictions of the performance of these switchable devices in device applications, enabling...
RFID has been widely used around the world and it is necessary and effective to lower the cost of RFID by removing inside chip. A novel frequency-coded chipless RFID tag is presented in this paper. It encodes data into the spectral characteristic by spiral resonators with different structures. The tag with six resonators can produce totally 64 IDs and each tag has its unique ID decided by unique size...
This paper put forward a windmill-shaped left-handed metastructure, which consists of four central-symmetric spiral lines and four metallic sticks. An equivalent circuit of the left-handed unit is modeled based on transmission line theory. Then a multi-band antenna is designed by applying this windmill-shaped unit, just with central-symmetric spiral and cross-bar slits loaded on a rectangular patch...
Characteristic mode (CM) theory for modal analysis of microstrip antennas is developed in this paper. It is derived from the mixed-potential integral equation (MPIE) with spatial domain Green's functions for multilayered media, where the spatial domain Green's functions take into account the effect of the multilayered media. Numerical results are presented to confirm its effectiveness and accuracy...
This paper presents the project of WLAN antenna made in microstrip technique working at a frequency of 5 GHz in 802.11ac IEEE standard. The paper presents the results of discussed numerical analysis.
The performance of the Improvised Absorbing Boundary Conditions (IABC) is studied when applied to wireless power transfer (WPT) systems. The IABC is one of the approximated techniques to solve the unbounded electromagnetic problems. It was recently proposed to solve quasi-static problems and extended to the high frequencies. Non-radiative WPT based on the magnetic resonance and near-field coupling...
In this paper a novel THz resonator based on Cherenkov Effect in photonic crystal waveguide is proposed. Cherenkov radiation can be generated by an electron beam crossing with the dispersion curves of photonic crystal waveguide at 8.23 GHz. A microcavity can be constructed by decreasing some radius of rods in the waveguide. The resonance frequency of the microcavity can be adjusted to be consistent...
In this paper a dipole-type RFID tag antenna is proposed and it can be used to detect the mechanical deformation of an object. When the tag antenna is attached to an object, the mechanical deformation of the object and the patch antenna will contribute to the frequency deviation. So we can research and test the impact of mechanical deformation of the RFID tag antenna on its resonant frequency to monitor...
In this work, a novel bi-layered metamaterial structure composed of a ring-chain structure and metal sheet-backed is proposed, which can realize ultra-broadband reflected polarization conversion in the near-infrared spectral region. Numerical results reveal that the structure possesses the ability to convert x-polarized and y-polarized waves to their orthogonal direction in frequency range from 109...
In this paper, an approximate model is presented to understand Fano resonances observed in the Mie scattering from a core-shell particle with high permittivity cover. The scattering coefficients of a core-shell particle with high permittivity cover can be described by the superposition of narrow resonance and slow varying background. The slow varying background part is the same as scattering coefficient...
At THz frequencies, indium antimonide (InSb) exhibits a negative permittivity, leading to the excitation of a surface plasmon resonance (SPR) [1]. In this work, we investigate the transmission characteristics of THz filters with the localized SPR excited around InSb square patches using the three-dimensional finite-difference time-domain method. First, we use an FR4 substrate with a thickness of 500...
In this work, we study the terahertz multichannel filtering properties based on a stage 3 triadic-Cantor-set semiconductor photonic crystal. Here, we use the semiconductor of n-InSb so that transmission responses have three regions. Two regions with frequencies well above and below the resonant frequency, the permittivity functions are nearly a positive constant. In these two regions, transmittance...
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