Intrinsic characteristics of transmission line of graphenes at microwave frequencies

2012 ◽  
Vol 100 (22) ◽  
pp. 223102 ◽  
Author(s):  
Hee-Jo Lee ◽  
Eunho Kim ◽  
Jong-Gwan Yook ◽  
Jongwan Jung
Keyword(s):  
Transmission Line ◽  
Microwave Frequencies

scholarly journals Broadband transmission-line illusions based on transformation electromagnetic

2019 ◽  
Vol 6 ◽  
pp. 23
Author(s):  
Tsutomu Nagayama ◽  
Atsushi Sanada
Keyword(s):  
Transmission Line ◽  
Incident Angle ◽  
Near Field ◽  
Homogeneous Medium ◽  
Field Measurements ◽  
Dielectric Substrate ◽  
Frequency Range ◽  
Microwave Frequencies ◽  
Intrinsic Nature ◽  
Line Technology

We demonstrate broadband transmission-line illusions based on transformation electromagnetics at microwave frequencies by using the distributed full-tensor anisotropic medium. Due to an intrinsic nature of the non-resonant unit cell of the medium, the illusions operate from DC to an upper limit frequency where the homogeneous medium approximation holds. Two-dimensional groove and bump illusion media mimicking scattered waves by an original groove and a bump are designed. Their broadband and incident angle independent operations are confirmed by circuit simulations. The groove illusion medium is implemented on a dielectric substrate with microstrip-line technology, and it is confirmed experimentally by near-field measurements that the illusion medium well mimics scattered waves by the original groove in the broadband frequency range from 2.60 GHz to 4.65 GHz.

scholarly journals Smaller-loss planar SPP transmission line than conventional microstrip in microwave frequencies

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Hao Chi Zhang ◽  
Qian Zhang ◽  
Jun Feng Liu ◽  
Wenxuan Tang ◽  
Yifeng Fan ◽  
...  
Keyword(s):  
Transmission Line ◽  
Microwave Frequencies

scholarly journals Effect of different permeability on electromagnetic properties of absorbing materials

2018 ◽  
Vol 197 ◽  
pp. 02015 ◽  
Author(s):  
Riser Fahdiran ◽  
Yuliyanti Dwi Utami ◽  
Erfan Handoko
Keyword(s):  
Transmission Line ◽  
Reflection Loss ◽  
Single Layer ◽  
Electromagnetic Properties ◽  
Complex Permeability ◽  
Transmission Line Theory ◽  
Microwave Frequencies ◽  
Microwave Absorbing Properties ◽  
Absorbing Materials ◽  
Line Theory

In this study, we have simulated and investigated electromagnetic properties of six types materials using a single layer metal backed absorber model that were determined at microwave frequencies 8.2 up to12.4 GHz. The reflection loss was simulated for different thicknesses in the range of 0.85 to 1.05 mm based on the relative complex permeability and permittivity referring to transmission line theory. The optimal microwave absorbing properties was be resulted by A3 sample. The minimum RL of −23.84 dB can be obtained at 10.72 GHz with thin thickness of 0.95 mm. This method paves a new avenue to design magnetic and dielectric absorbing materials.

scholarly journals Computational and Experimental Approaches for Determining Scattering Parameters of OPEFB/PLA Composites to Calculate the Absorption and Attenuation Values at Microwave Frequencies

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1919
Author(s):  
Ahmad Fahad Ahmad ◽  
Sidek Hj Ab Aziz ◽  
Zulkifly Abbas ◽  
Daw Mohammad Abdalhadi ◽  
Ahmad Mamoun Khamis ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Transmission Line ◽  
Polylactic Acid ◽  
Oil Palm ◽  
Loss Factor ◽  
Empty Fruit Bunch ◽  
Absorption Loss ◽  
Microstrip Transmission Line ◽  
Microwave Frequencies ◽  
Commercial Software Package

This article describes attenuation and absorption measurements using the microstrip transmission line technique connected with a microwave vector network analyzer (Agilent 8750B). The magnitudes of the reflection (S11) and transmission (S21) coefficients obtained from the microstrip transmission line were used to determine the attenuation and absorption of oil palm empty fruit bunch/polylactic acid (OPEFB/PLA) composites in a frequency range between 0.20 GHz and 12 GHz at room temperature. The main structure of semi-flexible substrates (OPEFF/PLA) was fabricated using different fiber loading content extracted from oil palm empty fruit bunch (OPEFB) trees hosted in polylactic acid (PLA) using the Brabender blending machine, which ensured mixture homogeneity. The commercial software package, Computer Simulation Technology Microwave Studio (CSTMWS), was used to investigate the microstrip line technique performance by simulating and determine the S11 and S21 for microwave substrate materials. Results showed that the materials’ transmission, reflection, attenuation, and absorption properties could be controlled by changing the percentage of OPEFB filler in the composites. The highest absorption loss was calculated for the highest percentage of filler (70%) OPEFB at 12 GHz to be 0.763 dB, while the lowest absorption loss was calculated for the lowest percentage of filler 30% OPEFB at 12 GHz to be 0.407 dB. Finally, the simulated and measured results were in excellent agreement, but the environmental conditions slightly altered the results. From the results it is observed that the value of the dielectric constant (εr′) and loss factor (εr″) is higher for the OPEFB/PLA composites with a higher content of OPEFB filler. The dielectric constant increased from 2.746 dB to 3.486 dB, while the loss factor increased from 0.090 dB to 0.5941 dB at the highest percentage of 70% OPEFB filler. The dielectric properties obtained from the open-ended coaxial probe were required as input to FEM to calculate the S11 and S21 of the samples.

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