Modified Split Ring Research Articles

Fractal metasurface for THz applications with polarization and incidence angle insensitivity

A Fractal metasurface-based absorber is designed to obtain a wideband absorption in THz frequency band. The developed absorber has a broadband absorption over more than 600 GHz bandwidth, from 0.6 THz to 1.2 THz, with a minimum absorption percentage of 70% and total absorption from 1 to 1.1 THz. The proposed fractal structure is investigated using a Modified Split Ring Resonator (MSRR). The absorption coefficient of the proposed fractal metasurface is compared with the modified initially SRR metasurface. The results indicate that by using fractal design, the metasurface operating band is summed up, resulting in a wide bandwidth. The absorption coefficient of the proposed fractal metasurface is studied using two different simulation software programs to ensure the obtained results, with a high agreement between the results of them. The designed metasurface has a similar absorption response for the different polarization of the incident wave. The impedance of the designed metasurface indicates that, for the operating band, the fractal metasurface has a surface impedance of around 377 Ω, indicating a good matching between the designed metasurface and air. Different incidence and polarization angles are studied with results showing its insensitivity to both of them. The designed metasurface is compared with previously published works, showing wider bandwidth, higher absorption, and incidence and polarization insensitivity. The proposed metasurface absorber can be used for biomedical applications.

Modified Split Ring Resonators Sensor for Accurate Complex Permittivity Measurements of Solid Dielectrics.

In this paper, a sensor using modified Split Ring Resonators (SRRs) is designed, simulated, fabricated, and used for advanced investigation and precise measurements of the real part and imaginary part solid dielectrics’ permittivity. Adding vertical strips tightly coupled to the outer ring of the SRR leads to the appearance of two resonant frequencies at 1.24 GHz and 2.08 GHz. This modified geometry also assures an improved sensitivity. Using the full wave electromagnetic solver, both the unloaded and loaded sensors are investigated. The numerical simulations are used to develop a mathematical model based on a curve fitting tool for both resonant frequencies, allowing to obtain analytical relations for real and imaginary parts of permittivity as a function of the sample’s thickness and quality factor. The sensor is designed and fabricated on 1.6 mm thick FR-4 substrate. The measurements of different samples, such as transparent glass, acrylic glass, plexiglass, and Teflon, confirm that the modified SRR sensor is easy to implement and gives accurate results for all cases, with measurement errors smaller than 4.5%. In addition, the measurements highlight the importance of the second resonant frequency in the cases in which numerical limitations do not allow the usage of the first resonant frequency (1 mm thick sample).

Design and Research of Modified Split Ring Resonator for Reduction of Mutual Coupling in Microstrip Patch Antenna Array

In this document, we proved a new technique for eliminating the impact of mutual connection amongst elements in an antenna array by integrating the Metamaterial Hybrid Split Ring Resonator (HSRR). The HSRR suggested unit-cell consists of a single circular ring resonator, each rounded with two symmetrical divisions, with one hexagonal ring resonant. The insulation of over 13 dB without affecting the working frequency and radiation features shall be accomplished by integrating the HRSR metamaterial framework near the correct side of the standard radiating patsch of the antenna array running at 2.4 GHz. The efficiency of the HSRR antenna array proposed has been numerically assessed

Sub wavelength plasmonic nano-antenna with modified SRR structure for Fano resonance

The optical electric field enhancement in the normal direction is noticed for Plasmonic and Fano mode at Nano antenna, therefore, we have modeled four various designs for Sub-wavelength Plasmonic and Nano-antenna with modified Split Ring Resonator (SRR) by adding new capacitors and SRR element to achieve the Fano resonance mode in various incident wave angles. Here, for all structures, the E-field enhancements at resonances are compared and design parameters effect on Fano resonance is debated. The incident wave direction is studied for making multi Fano resonance in all prototype structures and the extinction cross section comparison for 0°, 45° and 90° is revealed that the FANO resonances are related to the polarization angle of the incident wave and size of the gaps in Nano particles. SiN Substrate is selected with refractive index of 1.98 and silver with Johnson optical characteristic has been used for modeling of the metal layer. It has been observed that the |E2|/|Eint2| increased to 200000 at Fano resonances and the parametric studies showed that the gap size controls the Fano resonance frequency.

Multi-band phase shifter design using modified slotline configuration

In this paper, an analog multiband phase shifter using slotline configuration is proposed. To implement the design, a pair of modified Split Ring Resonator (SRR) is employed. The periodic property of SRR provides multiband characteristics, whether the coupling slot gives the phase variations over the bands. The operation is well explained with an equivalent circuit model and its characteristics have been studied both in simulation and measurement. The prototype operates in 1.77–2.16, 3.5–3.97, 5.08–5.33, 6.43–6.93, and 8.01–8.59 GHz frequency bands which can be utilized for GSM, GPS, WLAN, C-band, and X-band applications, respectively.

Evaluating High Temperature Modulus and Strength of Alumina Tube in Vacuum by a Modified Split Ring Method

Alumina is a typical ceramic material and possesses high strengthand stiffness at both room temperature and high temperature. The split ring methodhad been established to evaluate the elastic modulus and bending strength of aluminatube materials at ambient temperature. However, both equations for modulus andstrength became lightly inapplicable with the increased temperature. For theelastic modulus, it was lack of precise approaches and advices for deformationmeasurement in the heating furnace. For the bending strength, changes of sampledimensions due to thermal expansion would take an effect on the calculatingresults. In this work, several improvements have been taken into account tocalibrate the above deviations. Results revealed that the modulus and strengthregularly decreased from room temperature to 1300 °C and accorded well with other conventional testing methods.It proved the accuracy and reliability of this modified split ring method,which might be used to evaluate other ceramic tube materials at hightemperature.

Evaluation of Elastic Modulus of Quartz Glass Tube at High Temperature by Modified Split Ring Method

Evaluation of Elastic Modulus of Quartz Glass Tube at High Temperature by Modified Split Ring Method

Characteristics of Microstrip Fractal Antenna Shape Covered by Modified Split Ring Resonator

Metamaterials exhibiting negative index of refraction has attracted a great amount of attention in recent years. These materials are artificial structures that exhibit characteristics not found in nature. Microstrip antennas covered by metamaterial are one of the interesting areas of study. In this paper fractal shape antenna is proposed and covered by two layers of modified split ring resonator. The results shows an enhancement in Reflection Coefficients, gain, directivity and far field shapes.