Negative permittivity behavior and magnetic performance of perovskite La1−xSrxMnO3at high-frequency

2014 ◽  
Vol 2 (6) ◽  
pp. 1028-1033 ◽  
Author(s):  
Ke-lan Yan ◽  
Run-hua Fan ◽  
Zhi-cheng Shi ◽  
Min Chen ◽  
Lei Qian ◽  
...  
Keyword(s):  
High Frequency ◽  
Negative Permittivity ◽  
Magnetic Performance

High Frequency Soft Magnetic Performance on Magnetically Isotropic Co-Al-N Films in External Bias Field

2012 ◽  
Vol 48 (11) ◽  
pp. 2910-2913 ◽  
Author(s):  
H. Kijima ◽  
Y. Zhang ◽  
N. Kobayashi ◽  
S. Ohnuma ◽  
H. Masumoto
Keyword(s):  
High Frequency ◽  
Bias Field ◽  
Soft Magnetic ◽  
Magnetic Performance ◽  
External Bias

Complex Permittivity and Permeability Spectra of Nickel/Polyphenylene Sulfide Composite in Radio Frequency Range

2017 ◽  
Vol 898 ◽  
pp. 1757-1763
Author(s):  
Guo Hua Fan ◽  
Run Hua Fan ◽  
Zhong Yang Wang ◽  
Pei Tao Xie ◽  
Min Chen ◽  
...  
Keyword(s):  
High Frequency ◽  
Conduction Mechanism ◽  
Plasma Oscillation ◽  
Polyphenylene Sulfide ◽  
Negative Permittivity ◽  
Electromagnetic Properties ◽  
Double Negative ◽  
Frequency Range ◽  
Free Electrons ◽  
Negative Materials

Due to the distinct electromagnetic properties, double negative materials have bright application prospect in many areas in the future. The nickel (Ni)/polyphenylene sulfide (PPS) composites were prepared by hot pressing Ni and PPS powders mixture. Microstructures, dielectric properties, and magnetic performances of the resulted composites were studied in detail. Once Ni contents exceeded the percolation threshold, the conductive networks would form and the conduction mechanism would change from hopping conduction to metal-like conduction. Due to the plasma oscillation of the free electrons within the conductive networks, negative permittivity appeared. Interestingly, circuit loops in the connected Ni particles induced by external electric field resulted in a diamagnetic phenomenon under high frequency for the composite with ferromagnetic Ni particles.

Tunable negative permittivity and magnetic performance of yttrium iron garnet/polypyrrole metacomposites at the RF frequency

2019 ◽  
Vol 7 (11) ◽  
pp. 3160-3167 ◽  
Author(s):  
Chuanbing Cheng ◽  
Runhua Fan ◽  
Guohua Fan ◽  
Hu Liu ◽  
Jiaoxia Zhang ◽  
...  
Keyword(s):  
Yttrium Iron Garnet ◽  
Negative Permittivity ◽  
Yttrium Iron ◽  
Magnetic Performance ◽  
Iron Garnet

Tunable negative permittivity and relaxation-type dispersion for permeability were evidenced in yttrium iron garnet/polypyrrole metacomposites.

scholarly journals Modified double dumbbell-shaped split-ring resonator-based negative permittivity metamaterial for satellite communications with high effective medium ratio

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Bellal Hossain ◽  
Mohammad Rashed Iqbal Faruque ◽  
Sikder Sunbeam Islam ◽  
Mohammad Tariqul Islam
Keyword(s):  
Numerical Simulation ◽  
High Frequency ◽  
Satellite Communication ◽  
Ring Resonator ◽  
Satellite Communications ◽  
Split Ring Resonator ◽  
Effective Medium ◽  
Unit Cell ◽  
Negative Permittivity ◽  
Split Ring

AbstractMetamaterial with negative permittivity demonstrate excellent performance in cutting-edge technology. Thus, this study modified the double dumbbell-shaped split-ring resonator (MDD-SRR) based negative permittivity for satellite communications. The proposed MDD-SRR unit cell comprises a square-shaped split-ring resonator and two dumbbell-shaped rings. Some parts of the outer square ring were extended to enlarge the electrical length which altered the inductance of the metamaterial unit cell. The dimension of the proposed unit cell is 9 × 9 × 1.524 mm3, fabricated on a Rogers RT6002 (lossy) substrate material. Based on the results, five resonances for the transmission coefficient were achieved at frequencies of 2.896 GHz, 8.11 GHz, 9.76 GHz, 12.48 GHz and 13.49 GHz, including the S, X and Ku band satellite communication frequency bands through numerical simulation in a high-frequency electromagnetic simulator Computer Simulation Technology (CST) microwave studio. Negative permittivity at frequencies ranging from 2.896–3.76 GHz, 8.11–8.592 GHz, 9.76–10.784 GHz, 12.496–12.768 GHz, 13.504–14.4 GHz, were observed and extracted using the Robust and Nicolson–Ross–Weir (NRW) methods. Meanwhile, an effective medium ratio (EMR) measured at 11.51 to 2.896 GHz specified the goodness of the metamaterial unit cell for satellite communication with higher bandwidth and gain. The simulated, circuit model and measured results that were compared for validation purposes indicated that the simulation results, the equivalent circuit model results and measured results occupied each other. Moreover, the numerical simulation of the double dumbbell-shaped metamaterial unit cell was performed using a High-Frequency Structure Simulator (HFSS) to confirm the results. To evaluate the parametric study, the proposed unit cell was subjected to change different substrate types, change of split gap of rings, change of direction of electromagnetic field propagation, and structural optimization. In conclusion, the S, X and Ku-bands in the proposed metamaterial are competent for satellite communications as they are also investigated using an array of a unit cell.

High-Frequency Negative Permittivity from Fe/Al2O3 Composites with High Metal Contents

2011 ◽  
Vol 95 (1) ◽  
pp. 67-70 ◽  
Author(s):  
Meng Gao ◽  
Zhi-cheng Shi ◽  
Run-hua Fan ◽  
Lei Qian ◽  
Zi-dong Zhang ◽  
...  
Keyword(s):  
High Frequency ◽  
Negative Permittivity ◽  
Metal Contents ◽  
High Metal

Negative permittivity in Fe–Si–Ni/epoxy magnetic composite materials at high-frequency

2016 ◽  
Vol 170 ◽  
pp. 113-117 ◽  
Author(s):  
Qing Hou ◽  
Kelan Yan ◽  
Runhua Fan ◽  
Kun Zhang ◽  
Zidong Zhang ◽  
...  
Keyword(s):  
Composite Materials ◽  
High Frequency ◽  
Negative Permittivity ◽  
Magnetic Composite
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