Computer Simulation Technology Software Research Articles

Left-handed metamaterial based on circular split ring (CSRR) resonator for microwave sensing Application

This paper presents a new metamaterial structure specifically designed to operate in the L, S, and C frequency bands. It is characterized by a small unit cell size of 15mm × 15 mm. The metamaterial's electromagnetic properties are thoroughly examined, utilizing FR-4 substrate material and copper circular split ring resonators (CSRRs). The Computer Simulation Technology (CST) software uses the finite integration technique (FIT) to precisely model the effective parameters over a frequency range of 0–6 GHz. In simulations and experiments, the structure demonstrates negative refractive index, effective permittivity, and effective permeability. The electric and magnetic field distributions within the unit cell are accurately characterized using vector fields. In addition, the equivalent circuit is simulated and depicted using ADS software, with comparisons drawn between the measured data and the simulated data. The experimental validation, conducted using six varying thicknesses of FR4 materials, verifies the resemblance between the simulated and the measured transmission coefficients. Moreover, the effective medium ratio (EMR) of the metamaterial is calculated to be 12.74, indicating its promising capabilities for microwave sensing applications. The examination of the sensor model uncovers such metrics as quality factors, frequency detection resolution (FDR) values, and sensitivities, all of which enhance our comprehension of the material's performance. This discovery has the potential to advance the development of sensing metamaterials, which could significantly impact various applications and enhance research in the field.

High accuracy graphene-based refractive index sensor: Analytical approach

A high-precision graphene-based refractive index (RI) sensor is suggested in this article. Because resonances represent a specific field distribution, optical sensors show a very high sensitivity to environment RI changes. These optical sensors' sensitivity is profoundly subordinate to the materials used in the sensor as well as the sensor structure. The structure of the proposed sensor consists of the following layers, respectively: gold layer, SiO2, graphene and the substance under test (analyte). The transmission line model (TLM) was also fully investigated for this absorber and the inductor and capacitor values related to the simulation were obtained. There was a suitable agreement between the simulation results and TLM. This sensor has nearly perfect absorption and the absorption peak of this sensor in the absorption curve is 99.99 % at 3.24 THz with an average quality factor of 11.39. This absorber-based sensor sensitivity to changing the test medium (analyte) RI is so high that with a very small change in the RI of the analyte, the absorption peak is shifted, and its frequency changes. This sensor sensitivity and figure of merit (FOM) to variation of the analyte RI 726 GHz/RIU 2.69 RIU-1 were acquired, respectively. The characteristics of this sensor can be adjusted by variating the bias voltage exerted on the graphene layer. The Computer Simulation Technology (CST) and Advanced Design System (ADS) software have been used to analyze this structure. This proposed sensor can be used as a good sensor in biomedical applications and early diagnosis of diseases such as leukemia and types of cancer and influenza.

Technology Focus: Deepwater Fields (May 2024)

Without belittling our industry’s work to arrest climate change, the fact remains that relentless global efforts to secure energy during the past 4 decades have led to only a 7% reduction in the contribution of fossil fuels to the global energy supply. In light of the historic outcomes of COP28 and the stringent agreement of 198 countries to steer away from fossil fuels, it is evident that today’s oil and gas industry is at a crossroads and in an unprecedented race with time to address the trilemma to develop a progressive multitier energy model to balance transitioning to a low-carbon industry with maintaining production and fortifying its commitment to a sustainable future. Empowering, leveraging, and capitalizing on the current investments of our industry in the rapidly developing technologies that are revolutionizing both the renewable and fossil-fuel landscapes are exigently and prudently needed to reach this cornerstone goal. These technologies—such as carbon capture, use, and storage; winds; hydrogen; bioenergy; and geothermal—form more than 28% of the total energy consumption targeted to reduce greenhouse-gas emissions by 2050 and have a close affinity to the existing resources of the oil and gas industry. Deepwater offshore developments have always been the forefront projects of the industry. After about a decade of fragile outlook and waning investment in these ventures, the trend is showing a dynamic rise since 2022 based on the number of sanctioned projects worldwide and the associated annual capital of more than $200 billion. This is a remarkable affirmation of the resilience of these assets and the confidence in a greener, safer, and more cost-effective future of the industry in general. Rigorous engineering remains the key platform to accomplish the dizzying array of complex work on a daily basis and the linchpin in elevating the performance of deepwater projects from acquisition to abandonment. Opportunity still abounds for the operators of these assets to thrive and endure for the upcoming decades through advancing engineering prowess, bolstering their assets’ designs and operability, and collaborating with counterparts on potential synergies. These are prudent measures to appraise and invest in well-grounded solutions in order to harness the full potential of deepwater developments and improve their operational and overall efficiencies. Recommended additional reading at OnePetro: www.onepetro.org. SPE 217802 Fracturing 30,000-ft Wells in Deepwater—Planning and Execution Learnings From the Gulf of Mexico by K.F. Lizak, Shell, et al. OTC 32808 Validation of a Completion Digital Twin Applied to Packer Setting by L.A. Oliveira, Engineering Simulation and Scientific Software, et al. SPE 217277 Methane Recovery With Carbon Dioxide Sequestration as Hydrates in Deep Marine Environments: An Extensive Examination of Potential, Technical Advancements, and Economic Feasibility by Saket Kumar Shrivastava, SLB, et al.

Simple Compact UWB Vivaldi Antenna Arrays for Breast Cancer Detection

In this study, at ultra-wideband (UWB) frequency band (3.1–10.6 GHz), we propose the use of compact 2:1 and 3:1 nonuniform transmission line Wilkinson power dividers (NTL WPDs) as feeding networks for simple 2 × 1 linear UWB Vivaldi tapered and nonuniform slot antenna (VTSA and VNSA) arrays. The 2:1 and 3:1 tapered transmission line (TTL) WPDs are designed and tested in this work as benchmarks for NTL WPDs. The VTSA array provides measured S11 < −10.28 dB at 2.42–11.52 GHz, with a maximum gain of 8.61 dBi, which is 24.39% higher than the single element. Using the VNSA array, we achieve 52% compactness and 6.76% bandwidth enhancement, with good measured results of S11 < −10.2 dB at 3.24–13 GHz and 15.11% improved gain (8.14 dBi) compared to the VNSA single element. The findings show that the NTL and Vivaldi nonuniform slot profile antenna (VNSPA) theories are successful at reducing the size of the UWB WPD and VTSA without sacrificing performance. They also emphasize the Vivaldi antenna’s compatibility with other circuits. These compact arrays are ideal for high-resolution medical applications like breast cancer detection (BCD) because of their high gain, wide bandwidth, directive stable radiation patterns, and low specific absorption rate (SAR). A simple BCD simulation scenario is addressed in this work. Detailed parametric studies are performed on the two arrays for impedance-matching enhancement. The computer simulation technology (CST) software is used for the simulation. Hardware measurement results prove the validity of the proposed arrays.

For wireless LAN application, microstrip patch antenna design in S-band

This article presents a 3.5 GHz rectangular microstrip patch antenna (RMPA) designed, studied, and analyzed for wireless LAN applications. Using Fr-4 as substrate material, whose dielectric permittivity is 4.3, patch thickness is 1.65 mm, and loss tangent is 0.025. A feeding line with an impedance of 50 Ω is utilized to supply the antenna with power. Computer simulation technology (CST) software has been used to design the antenna and origin pro software has been used to display the resulting figures from the simulation. The antenna simulation showed that the return loss is -56.82 dB; the directivity gain is 6.02 dBi, the bandwidth is 0.148 GHz, and the voltage standing wave ratio (VSWR) is 1.0028. The paper aims to increase the return loss, develop a standard VSWR, increase the directivity gain of the antenna, and improve the antenna bandwidth. The results of the proposed antenna were much better than previously published papers, which were suitable for wireless applications. This proposed antenna can be used for future wireless LAN applications.

Assessing the costs and benefits of dynamically positioned floating wind turbines to enable expanded deployment

In addition to technical and economic challenges, the offshore wind industry must also contend with environmental and socio-political concerns that constrain development. Here, the viability of dynamically positioned floating offshore wind platforms that could ameliorate these constraints is analyzed. Such a design can unlock deeper, less-contentious waters that are farther from shore and reduce environmental interactions in the ocean, thus expanding and improving deployment opportunities. While prior studies on this application only focused on energy performance, the resulting cost of energy and benefits have not yet been quantified. Although prior studies found that the energy-performance of this strategy does not show promise, it is possible that a full understanding of the costs and benefits will reveal a decision space where it makes sense. To address this gap in the literature, the cost penalty of this application compared to moored turbines is estimated here. A physical engineering model is used to compute the environmental loads on a floating offshore wind turbine to estimate the expected energy needed by the station-keeping thrusters and one potential environmental benefit—eliminated mooring chains. The models were validated using marine engineering simulation software. Dynamic positioning realizes a cost penalty of at least 30 U.S. dollars/megawatt-hour while eliminating up to 900 km of mooring chains for a 1-gigawatt array. Up to 3 megawatt-hours of stored energy are needed to station-keep during continuous low winds. Furthermore, dynamic positioning is more viable for turbines of intermediate size (8–10 MW) rather than larger turbines (15 MW). The results show that aerodynamic loads on the turbine fall sharply beyond the rated wind speed, operational and design improvements may further improve the viability of this application, and the energy performance of this application continually improves with added thrusters although the cost of energy does not.

Terahertz Uygulamaları için Grafen Malzemesine Dayalı Mikroşerit Bowtie Anten Tasarımı ve Optimizasyonu

The developments of the wireless communications technology, the Terahertz (THz) frequency band of the electromagnetic spectrum becomes promising and recently has the researchers’ attention to be utilized in several applications such as medical, indoor communications for personal networks, and the military applications. The main issues in this frequency band are the construction of a compact, high-performance antenna design; as in this frequency band, the material properties for conduction decrease as the frequency increases, and therefore the performance of the antenna diminishes. In this paper, we propose a graphene-based bowtie microstrip antenna, the performance of the graphene material in the THz frequency band is analysed based on the finite integration of the Computer Simulation Technology (CST) software. The graphene-based bowtie patch printed on a silicon dioxide substrate with a fully copper ground plane printed on its bottom. The proposed graphene plasmonic bowtie antenna covers a range of 0.1-10 THz band frequency with good gain in the range of 2-19 dBi in the mentioned band.

A High-Gain Directional 1 × 8 Planar Antenna Array for 2.4GHz RFID Reader Applications

This research paper deals with a directional high gain PCB [Formula: see text] antenna array for 2.4[Formula: see text]ISM band utilizations. To achieve this antenna array, a well-matched equal-split 9[Formula: see text]dB-power splitter is designed and integrated with the suggested antenna array. It exhibits a wide operating range of 506[Formula: see text]MHz (2.022–2.528[Formula: see text]GHz) and splits the feed power to 8 equal-in-phase output quantities. Then eight identical patch elements with good reflection coefficient, high gain and excellent radiation efficiency are connected at the eight-output ports of the 1 × 8-power divider in order to obtain an array antenna consisting of eight radiating elements. A quarter-wave impedance adapter is utilized to obtain a perfect matching of impedance between patches and the power divider. The suggested directional antenna resonates at 2.4[Formula: see text]GHz with good impedance matching via offering reflection coefficient [Formula: see text][Formula: see text]dB and voltage standing wave ratio (VSWR) of 1.16. Moreover, it offers good radiation traits like the enhanced gain of 14.76[Formula: see text]dB, an excellent radiating efficiency equals about 98.86% and a directional radiation pattern. Initially, the proposed planar directional antenna array has been designed and simulated utilizing high-frequency structure simulator (HFSS) EM simulation tool, the results are validated with another simulation tool via computer simulation technology (CST) software. This printed antenna array is a potential candidate to operate at around 2.4[Formula: see text]GHz for RFID reader utilizations due to its outstanding impedance and radiation characteristics.

Low thermal SRR metamaterial design with multi-layered structured for terahertz frequency applications

The goal of this study is to examine the effects of split-ring resonators (SRR) with compact square shapes at terahertz frequencies. Therefore, a unique and miniaturised SRR metamaterial was constructed in this work. Every simulation was performed by using the Computer Simulation Technology software to explore the radar cross-section (RCS), reflection and transmission coefficients. Furthermore, MATLAB software was adopted to calculate the characteristics of an effective medium for the recommended SRR metamaterial. The initial metamaterial structure consists of a single layer that exhibits lower peak points with unsatisfactory magnitude values. Therefore, by adopting the trial and error technique, a few parametric studies were conducted to select the optimised metamaterial. For instance, various square-shaped design analyses, investigation of different substrate materials with a dielectric constant between 3.5 and 11.9, multi-layer structures, and larger-scale analyses were explored in this work. According to the observation, the quintuple layer SRR design was adopted since it possesses multiple resonances with reasonable magnitude values at 2.58, 3.78, 7.54, 7.77, 8.21, 8.5, and 8.88 THz. Moreover, the proposed quintuple-layer metamaterial helps to reduce the RCS values from −128.5 to −90.93 dBm2 at 2.58 THz when adopting an array cell structure. Moreover, this work also examines and analyses the thermal distribution of the proposed quintuple-layer metamaterial at all resonance frequencies. The observation revealed only small temperature distribution discrepancies occurred on the design structure compared to all peak points. In a nutshell, the proposed quintuple-layer SRR metamaterial achieved the purpose of this research and is practically applicable for the terahertz frequency.

Dual-Band Metamaterial Microwave Absorber using Ring and Circular Patch with Slits

This paper proposes a dual-band metamaterial microwave absorber operating at 2.5 GHz and 5.8 GHz. The absorber consists of a ring and a circular patch with slits resonator structures printed on a FR4 dielectric substrate backed by a ground layer. The main advantage of the absorber lies in its design flexibility in which each absorption band is independent and can be individually tuned by changing the dimensions of each resonator structure. The absorber unit cell is simulated and parametrically optimized using Computer Simulation Technology (CST) software. The absorption mechanism is analyzed through surface current analysis. The absorber prototype, with dimensions of 200 × 200 × 1.6 mm3 and consisting of an array of 7 × 7 unit cells, is fabricated and experimentally investigated using antennas in free-space measurement. The absorber exhibits over 97% absorption at both resonance frequencies. Furthermore, the absorber is demonstrated to be applicable in sensing applications for dielectric constant determination. With its design simplicity, wide-angle receptive, and polarization insensitive behavior, it is envisaged that the proposed absorber will find practical use in absorbing and sensing applications.

Design of a Compact Microstrip Filtenna for Miniaturized Devices to Access Internet of Things Using Long Term Evolution

A filtenna or filtering antenna has both radiation and filtering functions and is an important module for the RF front-end of wireless devices. The main function of a filtering antenna is to filter out the out-of-band interferences from the adjacent bands. In this paper, the design of a compact coplanar microstrip filtering antenna at 2.6GHz band is presented. The antenna is designed for the miniaturized devices for the city connectivity to access the internet of things (IoT) services over 2.6GHz long term evolution (LTE) gateways. Filtering antenna is designed using hairpin bandpass filter integrated with semi-circular microstrip antenna. Filtering antenna is designed by computer simulation technology (CST) software and measurements are performed by vector network analyzer. Good impedance matching at 2.6GHz band is obtained for the filtering antenna by choosing appropriate dimensions of the hairpin bandpass filter. The simulated 10dB return loss bandwidth of filtering antenna is 4.65% with maximum gain of 1.9dB. Measured and simulated results agree well for the semi-circular filtenna.

Microstrip patch antenna design and simulation for S-band wireless applications operating at 3.5 GHz

In the modern world, wireless technology is one way to send information from one place to another. This technology is getting better and better with time, which significantly impacts the activities that make up daily living. This wireless application has the most impact on mobile and other technologies. This research paper shows the design and analysis of a 3.5 GHz microstrip patch antenna (MPA) for wireless applications. The substrate material is Roggers RT/duroid, which has a dielectric permittivity of 2.2 computer simulation technology (CST) software does antenna design and simulation. Some observed parameters are the S-parameter, antenna directivity gain, voltage standing wave ratio (VSWR), and bandwidth. From the simulation, the return loss, VSWR, directivity gain, and bandwidth are -50.4227, 1.0061, 7.43 dBi, and 122.1 MHz respectively. This study aims to find the best return loss, get the most directional gain, and get the VSWR closer to 1. When this antenna was used, the results were better than those in scientific journals and conferences. As a result, this antenna is anticipated to fulfill the requirements of various wireless communication applications effectively.

Detection and localization of LV winding radial deformation in transformers using electromagnetic waves - a feasibility study

Recently, online methods based on electromagnetic waves have been proposed to detect the mechanical defects of high voltage (HV) windings in power transformers. In this article, for the first time, the possibility of online detecting and locating the radial deformation (RD) of low voltage (LV) windings using electromagnetic waves is presented. In the proposed method, a high frequency and wideband signal is sent to a simplified model of transformer winding via small antennas. The antennas are connected to the inner side of the oil tank cover through Radio Frequency (RF) cables, so that online monitoring can be realized with minimal changes in the transformer structure. The data of the reflected signals in different states is recorded in a database and sorted as primary data bank. By comparing the results of the sound state with measured signals, the possible faults can be detected. In this paper, the detection and location of radial deformation is estimated by using regression tree based on three features. Several cases are simulated by Computer Simulation Technology (CST) software, and their verification are conducted by a setup in laboratory. Based on comparison results, it can be claimed that the proposed method has LV windings radial deformation online detecting and locating ability with an acceptable accuracy.

Accurate inverse design for high-efficiency and broadband terahertz devices by co-simulation with genetic algorithms

In this study, we combined MATLAB with the rigorous electromagnetic field simulation software Computer Simulation Technology to perform a co-simulation method for inverse design of high-efficiency and broadband THz metasurface devices. In the proposed design method, genetic algorithm (GA) is embedded to realize automatic and inverse design. Aiming toward the different requirements of high-efficiency and broadband THz metasurface devices, different objective functions are set to optimize the design of different types of THz metasurface devices. Based on the rigorous electromagnetic simulation and genetic algorithm, the proposed design method can realize automatic and inverse design with high reliability, compared to the theoretical model based on catenary e-field theory. This study provides an important guiding role and an efficient method for designing and optimizing required metasurface devices with practical applied value.

Modified E-Shape Rectangular Microstrip Patch Antenna with DGS for Wireless Communication

A modified E-shape dual bands rectangular microstrip patch antenna for wireless applications is presented in this paper. An E-slot Microstrip patch antenna with a defective ground structure method has been proposed and getting two bands at 1.9 GHz and 2.89 GHz with S11 -10dB. Defective ground structures provide a maximum gain and low insertion loss i.e., a gain of 3.16 dB, voltage standing wave ratio less than 2, and insertion loss less than -10 dB for both bands. The size of the antenna is 46.83mm x 38.41mm x 1.676mm, which is compact in term of size. The dual band microstrip patch antenna exhibits low cost. The simulation's outcome closely resembles the actual printed antenna and applicable for WiMAX application. The antenna was designed using the Computer Simulation Technology (CST) software and printed on FR-4 substrate.

The effect of the ground motion frequency content on seismic performance and fragility curve of special concentric braced frames

Several articles have investigated the effect of various seismic parameters on the response of the structure. However, there has been limited discussion on the impact of seismic frequency content on the brace failure modes and the collapse mechanism of this system. This study investigated the effect of this parameter, considering three special concentric bracing frames of 2, 4, and 6 stories. For the frame dynamic analysis, the open system for earthquake engineering simulation software (OpenSees) is used. To evaluate the effect of frequency content, 60 earthquake records with high, medium and low frequency content are selected from the pacific earthquake engineering research center ground motion database, considering the peak ground acceleration divided by the peak ground velocity ratio. Incremental dynamic analysis is conducted to draw fragility curves and examine the response of structures.The results indicated that the collapse capacity of structures decreased as the frequency content was reduced. The percentage of reduction in collapse capacity under earthquakes with high to the low frequency content in 2, 4 and 6 story structures were 68, 67 and 71, respectively. In fact, reducing the frequency content increased the probability of occurrence of low cycle fatigue mode in the brace.

A novel microwave-based non-destructive testing system for detection of sub-surface defects in natural flax fiber reinforced composite material

In the work presented here, microwave non-destructive testing using a rectangular waveguide loaded with a novel planar unit cell filter for the inspection of defects in the composite is studied. The proposed planar filter is designed as a unit cell with a copper (annealed) microstrip component on an FR-4 substrate. The waveguide loaded with the planar filter exhibits a reflection coefficient of −35.919 dB at a frequency of 10.548 GHz. This planar filter waveguide is used as the sensor probe for the non-destructive testing method proposed here and is aimed to increase the sensitivity by measuring the differences in permittivity of materials. Computer simulation technology software (CST studio suite) is used for implementing the design, simulation, and material/defect evaluation. The defects studied are voids, cracks, and delamination in an epoxy-based natural flax fiber-reinforced composite material. The performance-improved microwave sensor probe is used to pick up permittivity variations in the presence of defects in lax-based natural fiber-reinforced composite material.

Ultra-wide band antipodal Vivaldi antenna design using target detection algorithm for detection application

This work presents a technique for detecting targets between two walls using ultra-wide band (UWB) modified antipodal Vivaldi antenna (MAVA). The detection system works on principle of time domain reflectrometry (TDR) using through wall imaging (TWI). This technique utilized a vector network analyzer (VNA) to produced short and small pluses to irradiate through an antenna array system onto the wall under study. The purposed detection system operated in UWB frequency spectrum (3.1 GHz to 10.6 GHz). Furthermore, an algorithm for hidden target detection has been developed. The results of the simulation of the designed antenna revealed a significant level of penetration, demonstrating a smart advancement in detecting and imaging system, to locate hidden metallic targets with good accuracy. A signal processing technique have been employed to improve the resolution of the target image. Using computer simulation technology (CST) software, the development and optimization process of an antenna is carried out, and the parametric performance of return loss, directivity and radiation pattern is evaluated.

Application of molecular dynamics simulations in interface interaction of clay: Current status and perspectives

AbstractTo understand the research progress of molecular dynamics (MD) method in the field of clay minerals, the application of MD in the interface interaction of clay minerals is reviewed in this paper. MD simulations have become the indispensable means to study mineral interface effects. Clay minerals are common associated minerals with hydrophilic surface, the ease of argillization, negative electricity, and the ability of forming impurities and defects. They are widely concerned in the fields of mine wastewater treatment, fine clay mineral flotation, shale oil and gas exploitation, and so forth. In addition, clay minerals are considered as natural adsorbents due to their large specific surface area, but their complex interface interactions hinder their effective utilization. Therefore, it is particularly important to reveal the interaction mechanism of clay interface at the atomic/molecular level by means of software simulation technology. In this review, our focus is on the applications of MD method in the field of clay mineral interface interaction, such as clay/gas interface, clay/water interface, agents and clay/water interface, and mineral particle and clay/water interface. Furthermore, the history and shortcomings of MD simulation are summarized. The research and effective utilization of clay interface are summarized and prospected as well.

A Modified Polygon Shaped Microstrip Patch Antenna Array for Ultra-Wideband Applications

A single element and two elements array polygon shape microstrip antenna is proposed and analyzed in this paper for ultra-wideband (UWB) applications. The technique used to improve antenna performance is etching rectangular slots on the patch of the antenna with different dimensions and positions. Two Polygon Shape antenna patches are introduced to enhance the antenna properties. Also, multi-slots are reached to improve the antenna gain, impedance matching sweep parameter optimization technique is used to all antenna parameters to enhance antenna properties. The dimensions of the single element antenna are 30 x 33 mm2 and consist of a slotted polygon patch printed on an FR-4 substrate. The proposed antenna has a resonant frequency of 6.2 GHz, while the dimensions of two elements antenna array are 60 x 33 mm2 and the resonance frequency is 9.8 GHz. A technique of inset feed transmission line was utilized to match the 50 Ω microstrip feed line and the radiating patch. These considerations make the structure is suitable for fifth-generation generation (5G) mobile wireless applications. The proposed antenna was simulated by use Computer Simulation Technology (CST-2020) software.