Computer Simulation Technology Software Research Articles

Metasurface-Based Wideband MIMO Antenna for 5G Millimeter-Wave Systems

This paper presents a metasurface based multiple-input multiple-output (MIMO) antenna with a wideband operation for millimeter-wave 5G communication systems. The antenna system consists of four elements placed with a 90 degree shift in order to achieve a compact MIMO system while a 2x2 non-uniform metasurface (total four elements) is placed at the back of the MIMO configuration to improve the radiation characteristics of it. The overall size of the MIMO antenna is 24x24 mm2 while the operational bandwidth of the proposed antenna system ranges from 23.5-29.4 GHz. The peak gain achieved by the proposed MIMO antenna is almost 7dB which is further improved up to 10.44 dB by employing a 2x2 metasurface. The total efficiency is also observed more than 80% across the operating band. Apart from this, the MIMO performance metrics such as envelope correlation coefficient (ECC), diversity gain (DG), and channel capacity loss (CCL) are analyzed which demonstrate good characteristics. All the simulations of the proposed design are carried out in computer simulation technology (CST) software, and measured results reveal good agreement with the simulated one which make it a potential contender for the upcoming 5G communication systems.

A synchroscan streak tube with high deflection sensitivity

A synchroscan streak tube with high spatiotemporal resolution and high deflection sensitivity is proposed, which contains several innovation designs. Some measures are taken to improve the imaging performances of the streak tube. Firstly, in order to obtain a high deflection sensitivity, the difference in voltage between the photocathode and anode and the length of the equipotential region of the streak tube are reduced as much as possible. Secondly, by introducing a hyperfine grid behind the cathode, reasonably designing the voltages applied to the six-electrode electrostatic focusing system, and moving the electron beam crossing point to the entrance of the deflection plates, the temporal dispersion and the temporal distortion of the streak tube are reduced, and the spatiotemporal resolution of the streak tube is improved. Besides, the streak tube is technically analyzed by tracking the temporal and spatial distribution of electrons under an operating voltage of 7000 V with the aid of computer simulation technology (CST) software. The results show that the deflection sensitivity is 125 mm/kV, the physical temporal resolution is better than 1.83 ps @MTF = 10%, and the static spatial resolution on the photocathode is better than 38 lp/mm @MTF = 10% over the effective photocathode area with a size of 10 mm × 4 mm. By applying a synchronous scanning voltage with a repetition frequency of 250 MHz to the deflection electrode, the results show that the dynamic spatial resolution of the streak tube is better than 16 lp/mm, the limit of the dynamic temporal resolution is 1.39 ps, and two rectangular electron pulses with a size of 10 mm × 20 μm and an interval of 2.3 ps emitted from the photocathode can be well resolved by the streak tube. In addition, the experimental measurements are conducted with a streak tube developed in our laboratory. The results demonstrate that the photocathode of the streak tube can work in the entire visible light region, and the response in the short wavelength region is significantly better than that in the long wavelength region. The static spatial resolution of this streak tube is 40 lp/mm in the center of the photocathode. The temporal resolution of this streak tube is 5.55 ps measured under a synchronous scanning voltage with a repetition frequency of 75 MHz.

Design of Unlicensed Dual Band Quasi-Yagi Antenna Using Semi-Bowtie for Indoor Wireless Power Transfer Application

This paper focuses on antenna for harvesting energy from a dedicated transmitter. The potential novel quasi-Yagi antenna with semi-bowtie driven element can be used as part of rectenna due to its characteristic of having directional properties and considerably wide bandwidth covering the Industrial, Scientific, and Medical (ISM) band consists of 863-870 MHz band and 902-928 MHz band. The modified quasi-Yagi is designed on a low-cost FR4 substrate with a physical size of 130 x 100 mm2 equivalent to 0.35λo x 0.27λo. The antenna has a peak directivity of 2.7 dBi and peak gain of 2.2 dBi in the targeted unlicensed bands with bandwidth of 14.4% for the range between 0.820-0.944 GHz. The shift in the resonant frequency is achieved by varying the phase shifter length and maintaining the same width for consistency. The antenna's operating frequency range varies between 0.8 GHz until 1 GHz which is less than 1 GHz by using semi-bowtie as driven element with a specific 7.22⸰ flare angle. The phase shift arm length of the antenna has been studied and simulated by using Computer Simulation Technology (CST) software and verified by using analytical equations. The simulated results are in accordance with the results obtained using analytical method. The same antenna geometry except variation in phase shifter arm length has been used throughout the study for consistency. The proposed antenna is promising to be used as part of rectenna for powering power management chip such as BQ25570 in a smart house environment operating at the indicated ISM bands.

A Reconfigurable Notched Band Monopole Antenna for C-Band Applications

In this paper, a wideband monopole antenna with reconfigurable frequency notch through wireless local area network (WLAN) (5.15-5.35GHz and 5.725-5.825GHz) or future wireless fidelity 6GHz (Wi-Fi-6E) (5.925-7.125GHz) band for C-band applications is presented. The conventional/basic monopole antenna consists of four-leaf clover antenna structure with cascaded feeder and Defected Ground Structure (DGS). The basic antenna is designed and then simulated using Computer Simulation Technology (CST) and High-Frequency Structure Simulator (HFSS) readymade software programs. The antenna covering an operational bandwidth extends from 4.2GHz to 9.2GHz while the gain is around 4.0dBi. Two simple resonator conductors are added near the thin feeder of antenna to realize the notched frequency. The rejected frequency within WLAN or Wi-Fi 6E bands is controlled by the resonator conductor lengths, so Positive-Intrinsic-Negative (PIN) diodes switches are inserted to achieve the required length for each rejected band. Finally, each of the basic antenna and the proposed notched antenna are fabricated and measured. The measurement results are in good agreements with the simulated results of CST and HFSS, providing good antenna performance and sharp notches with good rejection values.

Molecular Cloning and Genetic Engineering Design, Simulation and Management Software for Complex Synthetic Biology

Molecular Cloning and Genetic Engineering Design, Simulation and Management Software for Complex Synthetic Biology

High gain antenna at 915 MHz for off grid wireless networks

This paper presents a high gain antenna for off-grid wireless networks at 915 MHz. The requirements for compact size and high gain antenna are needed in the industrial, scientific and medical (ISM) band for better performance and coverage. Hence, microstrip planar substrate is proposed to overcome the size challenges. The proposed antenna is designed based on rectangular patch with air gap technique. The proposed antenna is optimized using computer simulation technology software (CST) and fabricated on low profile FR-4 substrate. The measured performance agreed well with the simulated one. The reflection of less than -10 dB is obtained with high gain of 6.928 dB at desired frequency. Overall, this antenna can be a good candidate for the off-grid wireless network applications.

Design of Helical Antenna for Next Generation Wireless Communication

This study proposes a novel helical antenna design for next generation applications. The strip helical antenna is prescribed for next generation wireless communication and wideband applications that offer circular polarization and a wide bandwidth. In fact, the proposed helical antenna suits 5.8 GHz frequency by using Teflon material. The newly-designed strip was printed on a substrate and rolled into a helix shape to achieve circular polarization without impedance matching. This antenna is meant for wideband wireless communication applications. A wide bandwidth of 2.7 GHz with 5.8 GHz resonant frequency was attained through the use of helical antenna on Teflon substrate. The proposed antenna on Teflon substrate recorded a gain of 8.97 dB and 92 efficiency. The antenna design parameters and the simulated results were retrieved using Computer Simulation Technology software (CST). The measurement result of return loss displayed mismatch at 5.22 GHz due to manual fabrication. This developed antenna may be applied for a number of wireless applications, including Wideband, Ultra-wideband, and 5G. © 2020 Wydawnictwo SIGMA-NOT. All rights reserved.

Wideband frequency reconfigurable metamaterial antenna design with double H slots

This paper presents the design of wideband frequency reconfigurable metamaterial antenna with double H slots. The design is based on the idea of composite right/left-handed transmission line (CRLH-TL) technique. Bandwidth enhancement was achieved by utilizing series left-handed capacitor CL transmission line parameter. The design has several outstanding advantages which include efficient bandwidth to cover many lower Application bands with multi frequency operation characteristics. A comprehensive analysis and simulation were done by using computer simulation technology (CST) software to determine the performance and efficiency of the proposed antenna. From the result obtained, the antenna aquired bandwidth range which covered (2.3-5.2) GHz which is equivalent to 77% fractional bandwidth. The wideband antenna was reconfigured by using frequency reconfiguration technique. From the reconfiguration results, the antenna can be switch from wideband to two single bands which resonate at 2.4 GHz and 4.2 GHz and to dual band which resonate at 2.4 GHz and 4.2 GHz. The realized peak gain at 2.4 GHz is 2.28 dBi and 2.58 dBi for E and H field respectively. The maximum efficiency of 96% was obtained. The antenna can be use for WLAN, proposed lower 5G band and cognitive radio system for frequency sencing.

Research on Electrical Characteristics of Mixed Media Based on Computer Simulation Technology

Computer technology is mainly used to study the electrical characteristics of mixed media through calculation and analysis of its equivalent dielectric constant. Since the geometric distribution, content, and structural shape characteristics of different phases in the mixed media will affect the equivalent dielectric constant to varying degrees, we need to analyze the relevant factors. However, when analyzing the relationship between the geometric distribution characteristics of each phase and the equivalent permittivity in a mixed medium, the traditional hybrid formula analysis method cannot meet the actual needs of complex equivalent equivalent permittivity research. Therefore, we must adopt computer simulation technology and use relevant simulation software to realize the conversion between geometric distribution and correction factor. In addition, we can also modify the mixing formula through the porosity function to accurately understand the electrical properties of the mixed medium.

Prediction of Polymer Flow Length by Coupling Finite Element Simulation with Artificial Neural Network

In this study, computer-aided engineering (CAE) simulation software and the design of experiments (DOE) method were used to simulate the injection molding process in terms of the melt flow length, using a spiral part. Process parameters such as melt temperature, mold temperature, injection pressure and mold cavity thickness were considered as injection molding variables. A predictive model for the flow length was created using a three-layer artificial neural network (ANN). The ANN model was trained with both simulation and experimental data, and the predictive performances were compared in terms of correlation coefficient, root mean square error and mean relative error. The cavity thickness and melt temperature were found to be the most significant factors for both the simulation and the experiment, while the injection pressure and the mold temperature had little effect on the flow length. The ANN model trained with Moldex3D data shows a significantly higher prediction capacity than the ANN model trained with experimental data. However, the melt flow lengths predicted by the ANN model for both Moldex3D and Moldflow simulation data are statistically significant, indicating that the proposed prediction methodology, which combines the ANN model, DOE method and the CAE simulation technology, can effectively predict the flow length of injection molded parts, with a small number of data.

Electrode Model and Simulation of His- Bundle Pacing for Cardiac Resynchronization Therapy

Abstract A disturbed synchronization of the ventricular contraction can cause a highly developed systolic heart failure in affected patients with reduction of the left ventricular ejection fraction, which can often be explained by a diseased left bundle branch block (LBBB). If medication remains unresponsive, the concerned patients will be treated with a cardiac resynchronization therapy (CRT) system. The aim of this study was to integrate His-bundle pacing into the Offenburg heart rhythm model in order to visualize the electrical pacing field generated by His-Bundle-Pacing. Modelling and electrical field simulation activities were performed with the software CST (Computer Simulation Technology) from Dessault Systèms. CRT with biventricular pacing is to be achieved by an apical right ventricular electrode and an additional left ventricular electrode, which is floated into the coronary vein sinus. The non-responder rate of the CRT therapy is about one third of the CRT patients. His- Bundle-Pacing represents a physiological alternative to conventional cardiac pacing and cardiac resynchronization. An electrode implanted in the His-bundle emits a stronger electrical pacing field than the electrical pacing field of conventional cardiac pacemakers. The pacing of the Hisbundle was performed by the Medtronic Select Secure 3830 electrode with pacing voltage amplitudes of 3 V, 2 V and 1,5 V in combination with a pacing pulse duration of 1 ms. Compared to conventional pacemaker pacing, His-bundle pacing is capable of bridging LBBB conduction disorders in the left ventricle. The His-bundle pacing electrical field is able to spread via the physiological pathway in the right and left ventricles for CRT with a narrow QRS-complex in the surface ECG.

Design of multiband microstrip patch antenna with bandwidth enhancement for wireless communication system

This research work presents analysis of multiband rectangular microstrip patch antenna for globalsystem for mobile communications at 0.9455GHz and 1.7595GHz and wireless local area Network at 2.4635 GHZ and 5.15 GHz and WiMAX at 3.5745GHz and international mobile telecommunications (IMT) at 4.46 GHz . An antenna is designed using FR4-(epoxy) substrate material with thickness1.6 mm and dielectric constant of 4.3. The microstrip antenna has a patch dimension of 83.33mm×45mm. The antenna has minimum return loss of - 32.563 dB at 0.9455GHz, -27.226 dB at 1.7595 GHz, -29.136 dB at 2.4635GHz, -31.621 dB at 3.5745GHz, -36.531dB at 4.46 GHz, -25.613 at 5.15 GHz. In this antenna designed the maximum gain of 2.20 dB at 0.9455GHz, 3.17 dB at 1.7595 GHz, 5.68 dB at 2.4635GHz , 7.04 dB at 3.5745 GHz, 6.08 dB at 4.46GHz, 5.26 dB at 5.15 GHz. The simulation of the design antenna is done using the software computer simulation technology CST

A compact square-shaped left-handed passive metamaterial with optimized quintuple resonance frequencies for satellite applications

The research aims to develop a more sophisticated novel left-handed and compact square-shaped metamaterial (SM) inspired multi-frequency bands like C-, X- and Ku-band applications. Even though the performance of existing satellite application devices are adequate, significant changes in technology over the past decades require advanced and more accurate techniques or devices. Hence, we approach the problem with a broader perspective by integrating a metamaterial structure in satellite application devices. As a general rule, the unconventional material known as metamaterial has extraordinary electromagnetic properties which are impracticable in commercially available materials. It represents an important study topic because this type of peculiar material is generally used in many field applications which encouraged us to experiment with the stated frequency bands by introducing a novel SM design. The novel SM design structure involved a 1.6 mm Epoxy Resin Fibre (FR-4) substrate material. This compact metamaterial design contains nine square rings with an altered small square ring joined in it. The numerical simulation of the SM design for satellite frequencies was performed using the Computer Simulation Technology (CST) Microwave Studio. The scattering parameters of the suggested SM design were determined by utilising Finite Integration Technique (FIT) in CST software. Several parametric studies that were analysed in this study include various design structure, types of substrate materials and SM array arrangement. Based on the adapted simulated frequency range (4 to 18 GHz), the unit cell SM exhibited five resonance frequencies at 5.49 and 7.33 GHz (in C-Band), 9.05 and 11.38 GHz (in X-Band) and 13.48 GHz (in Ku-Band). The measured resonance frequencies of the unit cell were 5.62 and 7.39 GHz (in C-Band), 9.15 and 11.32 GHz (in X-Band) and 13.51 GHz (in Ku-Band). The resonance frequencies obtained from both methods were similar. According to all three resonance frequencies, the SM design manifested a left-handed characteristic. Hence, on this basis, the proposed SM design with unique characteristics is deemed suitable for C-, X- and Ku-bands applications.

A New and Compact Wide-Band Microstrip Filter-Antenna Design for 2.4 GHz ISM Band and 4G Applications

A new and compact four-pole wide-band planar filter-antenna design is proposed in this article. The effect of the dielectric material type on the characteristics of the design is also investigated and presented. The filter-antenna structure is formed by a fourth-order planar band-pass filter (BPF) cascaded with a monopole microstrip antenna. The designed filter-antenna operates at a centre frequency of 2.4 GHz and has a relatively wide-band impedance bandwidth of about 1.22 GHz and a fractional bandwidth (FBW) of about 50%. The effects of three different types of substrate material, which are Rogers RT5880, Rogers RO3003, and FR-4, are investigated and presented using the same configuration. The filter-antenna design is simulated and optimised using computer simulation technology (CST) software and is fabricated and measured using a Rogers RT5880 substrate with a height (h) of 0.81 mm, a dielectric constant of 2.2, and a loss tangent of 0.0009. The structure is printed on a compact size of 0.32 λ0 × 0.30 λ0, where λ0 is the free-space wavelength at the centre frequency. A good agreement is obtained between the simulation and measurement performance. The designed filter-antenna with the achieved performance can find different applications for 2.4 GHz ISM band and 4G wireless communications.

A Novel High Gain Wideband MIMO Antenna for 5G Millimeter Wave Applications

A compact tree shape planar quad element Multiple Input Multiple Output (MIMO) antenna bearing a wide bandwidth for 5G communication operating in the millimeter-wave spectrum is proposed. The radiating element of the proposed design contains four different arcs to achieve the wide bandwidth response. Each radiating element is backed by a 1.57 mm thicker Rogers-5880 substrate material, having a loss tangent and relative dielectric constant of 0.0009 and 2.2, respectively. The measured impedance bandwidth of the proposed quad element MIMO antenna system based on 10 dB criterion is from 23 GHz to 40 GHz with a port isolation of greater than 20 dB. The measured radiation patterns are presented at 28 GHz, 33 GHz and 38 GHz with a maximum total gain of 10.58, 8.87 and 11.45 dB, respectively. The high gain of the proposed antenna further helps to overcome the atmospheric attenuations faced by the higher frequencies. In addition, the measured total efficiency of the proposed MIMO antenna is observed above 70% for the millimeter wave frequencies. Furthermore, the MIMO key performance metrics such as Mean Effective Gain (MEG) and Envelope Correlation Coefficient (ECC) are analyzed and found to conform to the required standard of MEG < 3 dB and ECC < 0.5. A prototype of the proposed quad element MIMO antenna system is fabricated and measured. The experimental results validate the simulation design process conducted with Computer Simulation Technology (CST) software.

All-dielectric Metamaterial for Electromagnetically-induced Transparency in Optical Region

Metamaterial (MM) is emerging as a promising approach to manipulate electromagnetic waves, spanning from radio frequency to the optical region. In this paper, we employ an effect called electromagnetically-induced transparency (EIT) in all-dielectric MM structures to create a narrow transparent window in opaque broadband of the optical region (580-670 nm). Using dielectric materials instead of metals can mitigate the large non-radiative ohmic loss on the metal surface. The unit-cell of MM consists of Silicon (Si) bars on Silicon dioxide (SiO\(_{2}\)) substrate, in which two bars are directed horizontally and one bar is directed vertically. By changing the relative position and dimension of the Si bars, the EIT effect could be achieved. The optical properties of the proposed MM are investigated numerically using the finite difference method with commercial software Computer Simulation Technology (CST). Then, characteristic parameters of MM exhibiting EIT effect (EIT-MM), including Q-factor, group delay, are calculated to evaluate the applicability of EIT-MM to sensing and light confinement.

Left-handed Circular-Shaped Compact Metamaterial for X- and Ku-Band applications

The purpose of this paper is to propose a new circular-shaped metamaterial (CM) design for X- and Ku-band applications. The discovery of exotic characteristics in metamaterial encourages to carry out this research study. The proposed design is numerically simulated by utilising Computer Simulation Technology (CST) software. The CM structure consists of few circular rings that designed on 8 × 8 mm2 and 1.6 mm thick of FR-4 dielectric substrate material. The Finite Integration Technique (FIT) used to perform the simulation in CST. Frequency range of 4 to 18 GHz is adopted and the CM design manifest resonance frequencies at 8.19 GHz, 11.32 GHz (X-band) and 16.39 GHz (Ku-band). These resonance frequencies possess an acceptable magnitude values for instance, -30.70 dB, -22.59 dB, and -20.13 dB respectively. In additional, the proposed CM design exhibits left-handed characteristic at both resonance frequencies. Therefore, CM with unique behaviour can be applied for many current application fields such as satellite communication, wireless computer networks, weather monitoring, and etc.

Modal Analysis of Selected Measuring Bases and Their Impact on the Recorded Level of Surface Accelerations

In predicting the impact of vibrations propagated in a ground on newly designed construction objects, it is extremely important to reliably measure the time histories of velocity or acceleration at the site of the planned investment. As some studies show, the method of coupling accelerometers and geophones to the ground can affect not only the level of peak particle accelerations (PPA) or peak particle velocities (PPV)—commonly used in this type of evaluation—but also vibration frequency distribution of recorded signals. This makes it difficult to compare and analyze the results obtained by various research teams. Conclusions based on this type of comparison may be wrong. For this reason, it is extremely important that reliable dynamic measurements related to the propagation of ground surface vibrations should be carried out using not only appropriately selected measuring equipment (with the required sensitivity and measurement ranges—both in the time domain and frequency domain), but also the measurement bases/setups used for mounting various types of transducers, whose natural frequencies will be outside the frequency range relevant to the possible impact of vibrations on buildings and human beings inside. The paper presents the results of modal analyses carried out with the use of Ansys Engineering Simulation and 3D Design Software (based on the Finite Element Method) for three different types of measuring bases used to coupling accelerometers to the ground. Measuring bases selected for numerical analyses were in the form of a stiff steel spike of an X-shaped cross section (a measuring base No. 1) and two steel spikes of L-shaped cross-sections (a measuring bases No. 2 and No. 3). In the places of screwed accelerometers (three different types of IEPE/ICP transducers of varying sensitivity and a weight) point masses were attached to the measuring bases. As a result of the analyses, it was possible to determine the impact of individual methods of coupling of accelerometers to the ground on the reliability of recorded ground surface accelerations. Among others it was concluded that in each analyzed case the lowest natural frequencies of the measuring bases with attached accelerometers significantly exceeded 100 Hz. The widest frequency band free of resonance vibrations can be provided by the measuring base No. 3 (L50 × 50 × 5).

STUDY OF THE STRAIN STATE AND MOVEMENTS OF A FLEXIBLE ROD WITH INITIAL CURVATURE

Abstract. Aim. The possibility of obtaining the regressive part of the elastic (regressiveprogressive) characteristic under axial loading in the initial period is studied by applying an elastic rod having an initial curvature under vertical compressive load. The objective of the study is to determine the static characteristics of such a rod without taking the resistance forces into account. Method. To solve the problem, the elliptic parameters method was used to make a comparison with a solution obtained using the finite element method in the ANSYS engineering simulation software. Results. A technique was developed for assessing the strain state and displacements of a flexible rod with initial curvature in order to study the regression-progressive characteristic of various elastic systems having initial curvature for their effective use in determining oscillations. Conclusion. The obtained technique can be used to determine the deformed state of an elastic flexible rod having initial curvature and displacement of the point of application of force. At the same time, by setting various initial parameters of the flexible rod in order to obtain a regressive-progressive characteristic, significant displacements can be obtained in the subcritical region when the axial load does not exceed the Euler force for this flexible rod

Performance Analysis of Plasma Antenna with Different Shapes of Plasma Tube

This paper investigates analysis of a novel antenna design using plasma element instead of using metallic element as a conducting medium in transmit signal of radio frequency (RF). The main objective in this paper is to analyse the performance of plasma antenna using with different shapes of plasma tube. In this research, the simulation for four different designs (single tube, double tube, triple tube, and U-tube) with fixed gas (neon) and pressure (10 Torr) were conducted. Four different design tubes with constant length (160 mm) and diameter (10 mm), attached with coupling sleeve (copper) were used to analyze the electrical characteristic of electromagnetic wave propagation. Computer Simulation Technology (CST) was used to design the four custom made tubes and calculate the antenna parameters in terms of gain, return loss, directivity and radiation pattern. Plasma parameters were calculated by the CST software with frequency was set starting from 1 to 10 GHz for simulation based on the most effective range to get the best result. The results revealed that the triple tube has the highest gain of 3.247 dB with plasma frequency 1.22x109 rad/s and collision frequency 6.0985x108 collision/s. The three arrays on the triple tube gave the ability to transmit the input power into radiation in a specific magnitude is high. Although high gain obtained from the triple tube, U-tube shape gave the lowest Return Loss, S11 value which is -15.706934 dB. The results show the ability of plasma antenna to transmit and receive a signal which is a basic part of an antenna.