scholarly journals Isolation Improvement Technique for Two Closely Spaced Loop Antennas Using MTM Absorber Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hongmin Lee ◽  
Hyungsup Lee
Keyword(s):  
Ring Resonator ◽  
Split Ring Resonator ◽  
Unit Cell ◽  
New Method ◽  
Negative Permittivity ◽  
Split Ring ◽  
Antenna Structure ◽  
Complementary Split Ring Resonator ◽  
Permittivity And Permeability ◽  
Loop Antennas

This paper presents a new method to improve isolation between two loop antennas with absorber cells exhibiting negative permittivity and permeability at the aimed frequency of 2.54 GHz. The metamaterial (MTM) unit cell was constructed by two open complementary split ring resonator (OCSRR) and a split ring resonator (SRR) arrangement. The proposed antenna structure consists of two loop antennas occupying a space with the dimensions of51 mm×24 mm×2 mmand three absorber cells. The size of each absorber unit cell is7.4 mm×7 mm×2 mm. The isolation of more than 20 dB was achieved with three absorber cells loaded between two loop antennas; interantenna spacing (center to center) is 0.23λ0at 2.54 GHz. The results show that port-to-port isolation between two antennas can be improved with absorber.

scholarly journals Modified Hexagonal Split Ring Resonator Based on an Epsilon-Negative Metamaterial for Triple-Band Satellite Communication

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 878
Author(s):  
Salah Uddin Afsar ◽  
Mohammad Rashed Iqbal Faruque ◽  
Mohammad Jakir Hossain ◽  
Mayeen Uddin Khandaker ◽  
Hamid Osman ◽  
...  
Keyword(s):  
Satellite Communication ◽  
Ring Resonator ◽  
Negative Refractive Index ◽  
Split Ring Resonator ◽  
Metal Strip ◽  
Unit Cell ◽  
Negative Permittivity ◽  
Long Distance ◽  
Split Ring ◽  
Triple Band

A triple-band epsilon-negative (ENG) metamaterial based on a split ring resonator (SSR) with a modified hexagonal-shaped metal strip proposed in this study is a new combination of a single slit square resonator and a modified hexagonal-shaped metal strip. The desired unit cell FR-4 (lossy) that was selected as the substrate was 1.6 mm thick. Following the assessment of the unit cell, a high-frequency electromagnetic simulator like the computer simulation technology (CST) microwave studio was applied to assess the S-parameters. The proposed design exhibited resonance at 2.89, 9.42, and 15.16 GHz. The unit cell also demonstrated negative permittivity in the frequency ranges 2.912–3.728 GHz, 9.552–10.144 GHz, and 15.216–17.328 GHz, along with a negative refractive index. An effective medium ratio (EMR) of 11.53 is an indicator of the goodness of the metamaterial unit cell. It is deliberate at the lowermost resonance frequency of 2.89 GHz. Moreover, the simulated results that were validated using HFSS and equivalent circuit model indicated slight variations. The proposed design was finalised based on several parametric studies, including design optimisation, different unit cell sizes, various substrate materials, and different electromagnetic (EM) field propagations. The proposed triple band (S, X, and Ku bands) negative permittivity metamaterial unit cell can be utilised for various wireless applications, such as microwave communication, satellite communication, and long-distance radio communication.

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.

Characteristics of Left Handed Materials

2021 ◽  
Vol 19 (11) ◽  
pp. 01-14
Author(s):  
Thill A. Kadhum Al-Musawi ◽  
Samira Adnan Mahdi ◽  
Sundus Yaseen Hasan AL-Asadi
Keyword(s):  
Computer Simulation ◽  
Refractive Index ◽  
Ring Resonator ◽  
Split Ring Resonator ◽  
Negative Permittivity ◽  
Split Ring ◽  
Left Handed ◽  
Artificial Materials ◽  
Permittivity And Permeability ◽  
Gap Width

Researchers have been interested in studying so-called Left-Handed Metamaterials LHM, which are artificial materials. These materials have unusual characteristics, like negative permittivity and permeability, and therefore negative index. This paper has been discussed some characteristics of LHM by designing a square split ring resonator SRR and simulating with CST microwave studio (Computer Simulation Technology) to get S-parameters. The broadband frequencies (0-30) GHz were taking to specify the effective range of frequencies to work with, which was found to be between (8- 14) GHz. Then, the parameters of SRR have been varied such as split width on, gap width, metal width, rod width and metal material. The measurements show some of parameters have been affected the values of resonance frequency and the others are not. Also, the negative values of permittivity, permeability, and refractive index have been approved.

scholarly journals Complementary Split-Ring Resonator for Microwave Heating of µL Volumes in Microwells in Continuous Microfluidics

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 184
Author(s):  
Tomislav Markovic ◽  
Gertjan Maenhout ◽  
Matko Martinic ◽  
Bart Nauwelaers
Keyword(s):  
Microwave Heating ◽  
Ring Resonator ◽  
Casting Process ◽  
Split Ring Resonator ◽  
Sample Volume ◽  
Split Ring ◽  
Complementary Split Ring Resonator ◽  
Microwave Dielectric ◽  
Electric Field Direction ◽  
Made In

This work presents the design and evaluation of a planar device for microwave heating of liquids in continuous microfluidics (CMF) made in polydimethylsiloxane (PDMS). It deals with volumes in the µL range, which are of high interest and relevance to biologists and chemists. The planar heater in this work is conceived around a complementary split-ring resonator (CSRR) topology that offers a desired electric field direction to—and interaction with—liquids in a microwell. The designed device on a 0.25 mm thick Rogers RO4350B substrate operates at around 2.5 GHz, while a CMF channel and a 2.45 µL microwell are manufactured in PDMS using the casting process. The evaluation of the performance of the designed heater is conducted using a fluorescent dye, Rhodamine B, dissolved in deionized water. Heating measurements are carried out using 1 W of power and the designed device achieves a temperature of 47 °C on a sample volume of 2.45 µL after 20 s of heating. Based on the achieved results, the CSRR topology has a large potential in microwave heating, in addition to the already demonstrated potential in microwave dielectric sensing, all proving the multifunctionality and reusability of single planar microwave-microfluidic devices.

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