CST Studio Research Articles

Minaret Shape Micro-Strip Patch Antenna with Partial Ground Plane for Lower 5G and Wi-Max Applications

Antennas are a difficult component to design, yet they play critical functions in wireless transmission systems. To construct the required antenna, the antenna designer must overcome enormous challenges in getting all of the antenna's optimal qualities. Antenna designers must consider antenna factors like bandwidth, return loss, VSWR, gain, directivity, efficiency, and so on, for specific applications. So keep all parameter values as optimal as possible; sometimes you may need to adjust the design of the antenna from its standard shape. The present investigation describes the development of a partial ground-plane micro-strip patch antenna in the shape of a minaret for use in lower 5G and Wi-MAX networks. A microstrip patch antenna with a minaret-shaped radiating element and a partial ground plane is suggested. The suggested antenna is simple because it does not include any unwanted components on the patch, yet the significant gain is maintained by optimizing the ground plane's dimensions and position. The proposed antenna is constructed using a Rogers RT5880 (lossy) substrate, the line feeding method, and 0.035 mm thick (annealed) copper for the patch and ground components. CST Studio Suite 2018 is used for layout and modelling. The antenna is 28 x 16 x 0.79 mm3 and offers a maximum gain of 2.321 dB and a maximum directivity of 2.529 dBi. The recommended antenna has a frequency range of 3.3721 GHz to 4.2382 GHz, making it usable for both low-band 5G and Wi-MAX systems.

Performance Analysis of Wearable Antenna Worn in Close Proximity with Human Body

In the healthcare applications, wearable technology is being rapidly developed. Electromagnetic wave will have an effect when the passive antennas is being closed to the human body because it will act as lossy medium. In this study, the effect of human tissue properties will be studied and will carry out under three conditions: (1) in free space, (2) on human tissue (chest body part) with and without airgap, (3) single and double bended condition of the antenna. The spacing gaps between the antenna and the human chest has been set up such as 2 mm, 4 mm, 6 mm. The bending radiuses for both single and double condition also being set up as 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, and 12 mm. In this study, the effect of human body proximity and human body movement which caused bending to the wearable antenna are also analysed. It will be analysed using the CST Studio Suites 2021 Student Version software

A Compact MIMO Multiband Antenna for 5G/WLAN/WIFI-6 Devices.

This research work presents a compact design of a Multiple-Input Multiple-Output (MIMO) multiband antenna along with high-isolation characteristics. The presented antenna was designed for 3.50 GHz, 5.50 GHz, and 6.50 GHz frequencies for 5G cellular, 5G WiFi, and WiFi-6, respectively. The fabrication of the aforementioned design was undertaken using FR-4 (1.6 mm thickness) substrate material with a loss tangent and relative permittivity of about 0.025 and 4.30, respectively. The two-element MIMO multiband antenna was miniaturized to 16 × 28 × 1.6 mm3, making it desirable for devices operating in 5G bands. High isolation (>15 dB) was attained with thorough testing without employing a decoupling scheme in the design. Laboratory measurements resulted in a peak gain of 3.49 dBi and an efficiency of around 80% in the entire operating band. The evaluation of the presented MIMO multiband antenna was carried out in terms of the envelope correlation coefficient (ECC), diversity gain (DG), total active reflection coefficient (TARC), and Channel Capacity Loss (CCL). The measured ECC was less than 0.04, and the DG was well above 9.50. The observed TARC was also lower than -10 dB, and the CCL was below 0.4 bits/s/Hz in the entire operating band. The presented MIMO multiband antenna was analyzed and simulated using CST Studio Suite 2020.

Chipless RFID Sensors for IoT Sensing and Potential Applications in Underground Mining—A Review

Chipless radio frequency identification (RFID) sensors have enormous potential for underground mining applications since this technology has the potential to meet all the requirements, such as wireless communication, maintenance-free, long lifespan, and battery-free, required to deploy in harsh underground environments. This paper has analysed existing frequency domain chipless RFID sensor technologies to understand suitability for potential applications, such as environmental condition monitoring, support system stability detection, and health monitoring of mining structures in underground mining sites. In light of the analysis, the paper has presented a new classification based on sensing materials and intrinsic sensing parameters such as effective length, coupling, conductivity and permittivity. Furthermore, the analysis has considered accuracy, performance and readability using 3D Electromagnetic (EM) analysis software, CST Studio Suite. Finally, based on our critical analysis and experimental simulations, the paper has identified challenges that need to be addressed by future research for chipless RFID sensors in the underground mining application domain.

Design of Metamaterial Antenna Based on the Mathematical Formulation of Patch Antenna for Wireless Application

For WLAN/WIMAX applications, a brand-new tree-shaped metamaterial-loaded microstrip antenna is suggested. The reduced ground plane size and 4.4 dielectric constant (r) and 0.02 loss tangent (δ) dielectric are used to manufacture the 15 × 16 × 1.6 mm3 microstrip antenna. Two X-shaped slots are added to achieve the characteristics needed for WIMAX applications at 5.5 GHz. Additionally, a split-ring resonator is added to the structure to increase its bandwidth. It runs for WLAN applications with a center frequency of 5.8 GHz. The proposed structure’s measured impedance bandwidth is 45.39% with SRR and 53.48% without SRR, respectively. The proposed antenna is capable of satisfying the major requirements of modern wireless devices such as multiband operation, compact size, large bandwidth, and planar structure. The best outcomes are attained with the aid of parametric analysis of feed width, ground height, and slot width. All electromagnetic simulations were performed using CST Studio software. The measured results and the simulation agree. The waveguide extraction approach is used to demonstrate the SRR’s permeability property. The suggested antenna had adequate impedance matching, was small, and had a wide bandwidth.

Broadband measurements of the surface impedance in ferromagnetic wires as a boundary condition for scattering problems

In the cm-wave range, the skin depth is comparable to the micron radius of ferromagnetic wires and thus their magnetic and conductive properties will influence the scattered electromagnetic field. Solving the scattering problem by considering the complicated internal magnetic structure of the wire becomes unpractical. There is thus a need to develop hybrid methods when the external problem of scattering on an inclusion is solved together with the experimental impedance conditions on its surface. Herein, we propose an accurate broadband impedance measurement technique operating up to GHz. The printed circuit board measurement and calibration cells designed in this work allow flexibility in choosing external stimuli such as magnetic field, tensile stress, and heat. The experimental impedance can be then used as the boundary condition in electromagnetic simulations making it possible to model, predict and design wire-based composites using numerical solvers such as CST Studio Suite.

Combined Open-Slot and Monopole 8 × 8 High-Isolation Broadband MIMO Antenna System for Sub-6 GHz Terminals

In this article, an 8 × 8 MIMO antenna system with multidecoupling structures is proposed for the fifth-generation (5G) terminal applications. First, an antenna element consisting of an L-shaped open slot with dimensions of 5.6 × 5 mm2 and two bent-L-shaped monopoles with dimensions of 12.7 × 6.1 mm2 is introduced. Due to coupling feed technology, the initial open slot owns a wide bandwidth from 3.62 GHz to 4.82 GHz. For broadening the bandwidth of the initial antenna element, two bent-L-shaped monopoles are added to the open slot to adjust the input impedance. By optimizing the parameters of monopoles, the proposed antenna element has been finally determined and the bandwidth of the antenna element has been broadened (2.82 GHz to 5.23 GHz). Second, a dual antenna pair is constructed by placing the two antenna elements with an edge-to-edge distance of 27 mm in a mirror image placement; the 8 × 8 MIMO antenna system is brought about by symmetrically disposing four such antenna pairs with an edge-to-edge distance of 47 mm. Moreover, the isolation of two closely placed antenna elements is achieved by the parasitic strip-loading technique and defective ground techniques. Due to the decoupling techniques used in the 8 × 8 MIMO antenna system, the average isolation has been optimized from 13.2 dB to 21.9 dB and the total efficiency of each antenna element has been improved from a worst 20% to over 45%. Besides, the calculated mean efficiency gain is less than 1 dB, and the calculated envelop correlation coefficient (ECC) is lower than 0.01 for desired frequency bands. Furthermore, the proposed 8 × 8 MIMO antenna system has the measured broadband bandwidth from 3.28 GHz to 5.05 GHz (covering N77, N78, and N79 bands) and a compatible dimension for ultra-thin mobile phones. The simulated results of this work are all obtained from EM software CST STUDIO SUITE 2019. In general, the proposed 8 × 8 MIMO antenna system with a high-isolation property provides a hopeful solution to 5G ultra-thin mobile phones.

A Simulation Study of Triband Low SAR Wearable Antenna

The proposed paper presents a flexible antenna that is capable of operating in several frequency bands, namely 2.45 GHz, 5.8 GHz, and 8 GHz. The first two frequency bands are frequently utilized in industrial, scientific, and medical (ISM) as well as wireless local area network (WLAN) applications, whereas the third frequency band is associated with X-band applications. The antenna, with dimensions of 52 mm × 40 mm (0.79 λ × 0.61 λ), was designed using a 1.8 mm thick flexible kapton polyimide substrate with a permittivity of 3.5. Using CST Studio Suite, full-wave electromagnetic simulations were conducted, and the proposed design achieved a reflection coefficient below −10 dB for the intended frequency bands. Additionally, the proposed antenna achieves an efficiency value of up to 83% and appropriate values of gain in the desired frequency bands. In order to quantify the specific absorption rate (SAR), simulations were conducted by mounting the proposed antenna on a three-layered phantom. The SAR1g values recorded for the frequency bands of 2.45 GHz, 5.8 GHz, and 8 GHz were 0.34, 1.45, and 1.57 W/Kg respectively. These SAR values were observed to be significantly lower than the 1.6 W/Kg threshold set by the Federal Communication Commission (FCC). Moreover, the performance of the antenna was evaluated by simulating various deformation tests.

Genetic Algorithm and Particle Swarm Optimization Approach for Prediction of Physical Parameters of Rectangular-Shaped Microstrip Antenna

This study presents the results of two optimization algorithms for estimating the resonant frequency, bandwidth, feed point, and input impedance of a rectangular-shaped microstrip antenna. To minimize the design cost and design time, genetic algorithms and particle swarm optimization methods have been applied and compared. The antenna design parameters were considered by using a genetic algorithm (GA) and particle swarm optimization (PSO) is implemented in the MATLAB® environment. The calculation results were assimilated with other studies in the literature in terms of accuracy. The computational results of the optimized parameters are having a good agreement with the experimental results. The optimized antenna was modeled and verified by the analyses performed using the CST Studio Suite® software.

Design and analysis of a compact multi-band annular ring antenna for UWB applications

In this paper a compact annular ring micro strip patch antenna with modified ground plane is proposed for UWB applications. The dimensions of proposed antenna are 30 × 26 × 1.6 mm3 which was designed on FR4 substrate with the thickness of 1.6 mm, εr = 4.4 and loss tangent parameter 0.02. To enhance the impedance bandwidth of the antenna ground plane is modifiedby extruding an inverted L shape stub and defected with multiple I shaped slots. The radiator consists of annular ringpatch, two circular stubs and one rectangular stub is included to the patch to improve the bandwidth. To design and simulate the proposed antenna CST Studio Suite 2018 is used. The proposed antenna is found with UWB frequency range of 3.1–10 GHz (S11 < −13 dB). Multiple frequency bands are observed in UWB frequency range 3.18 GHz, 6.75 GHz and8.67 GHz with the reflection coefficients of −49.6 dB, −50.2 dB and −45.7 dB respectively. VSWR is less than 2 for the total UWB frequency range. Proposed antenna is better option for UWB applications specially First and third frequency bands (3.18 GHz and 8.67 GHz) are suitable for Radio location (G59) services and second frequency band (6.75 GHz) is suitable for satellite and TV broadcasting applications. Performance of the proposed antenna is evaluated in terms of size, radiation efficiency and radiation patterns and it is better compared with existed systems.

Ultrahigh-Frequency Hop Dryer with Tiered Resonators

Introduction. From the analysis of hop dryers of different systems and designs follows the prospect of hop drying by complex influence of the energy of the electromagnetic field of ultrahigh frequency and convective heat. Aim of the Article. The article aims at developing a small-sized microwave convective hop dryer with justified parameters for intensive drying technology of freshly harvested hops. Materials and Methods. Taking into account the justified criteria for the design of a hop dryer and the analysis of existing resonators, there was proposed a methodology for the development of a hop dryer with an energy supply in an electromagnetic field, including requirements for structural design, operational and economic indicators, and technology. The electrodynamic parameters of the resonator were investigated according to the CST Studio 2017 program. Results. The dielectric parameters of hops are theoretically investigated and functional dependences on humidity at a frequency of 2,450 MHz are obtained. The dynamics of hop heating is investigated when its dielectric loss factor changes during the action of an ultrahigh frequency electromagnetic field. There has been developed a design and technological scheme of a radio-hermetic microwave convective hop dryer of continuous flow action with tiered resonators for low-power agricultural enterprises. Resonators are arranged in tiers in the screening cylindrical housing: the first and third resonators are hemispherical, and the middle one is made in the form of an ellipsoid to ensure a high electric field strength. The transportation of raw materials takes place by rotating the discs in a gentle mode. Discussion and Conclusion. The expected specific energy costs of a hop dryer with a capacity of 12–13 kg/h at the microwave generator power of 4.0 kW for drying freshly harvested hops with a humidity of 76–82% to a humidity of 11–14% are 0.30–0.33 kWh/kg. The required electric field voltage of 2 kV/cm in all three resonators is provided, therefore, disinfection of raw materials occurs at a temperature of 65–70°C for 5–6 minutes of stay in three resonators. The intensity of moisture release from hop cones during endogenous convective heating increases 5–6 times compared to the convective drying method. The introduction of microwave drying technology using a convective method of evaporation and removal of moisture from the drying chamber reduces the duration of the process, saves valuable components of cones for brewing.

Design of a Novel Efficient High-Gain Ultra-Wide-Band Slotted H-Shaped Printed 2×1 Array Antenna for Millimeter-Wave Applications with Improvement of Bandwidth and Gain via the Feed Line and Elliptical Edges

This paper describes design procedure of a high-performance miniaturized antenna with an array configuration, which contributes to enhancing the communication system’s performance. The basic antenna features a compact size (6 x 6) mm2, and its single element is an H-shaped slotted patch printed on the top side of a Rogers RT5880 substrate, with a relative permittivity and thickness of 2.2 and 0.3 mm, respectively. The edge-to-edge distance of the 2 × 1 array antenna is 9 x 14 mm2, and the isolation between its radiation elements is 4.5 mm. To increase the capabilities of the antenna in terms of gain and bandwidth, we proceeded to use the 2 × 1 array configuration and then optimized the model via either the width of the feed line or the elliptical edges of the patch. The miniaturized array antenna achieved a peak gain of 12.56 dB, a directivity of 13.11 dBi, and a return loss of -47.52 dB at a resonance frequency of 91.5 GHz, with a radiation efficiency of more than 91% over an operating bandwidth of 15.83 GHz, ranging from 79.7 GHz to 95.6 GHz. The design and simulation results of the proposed antenna were obtained using the CST Studio software.

Simulation of Dielectric Properties of Nanocomposites with Non-Uniform Filler Distribution

Dielectric properties for nanocomposites with metallic fillers inside a polymer matrix were determined using CST STUDIO SUITE-Electromagnetic field simulation software followed by the free-space Nicolson-Ross-Weir procedure. The structure is randomly generated to simulate the intrinsic non-uniformity of real nanomaterials. Cubic insertions were equated to corresponding spherical particles in order to provide either the same volume index or the same exterior surface index. The energy concentration around the inserts and within the entire material was determined as useful information in practice in order to design materials tailored to avoid exceeding the field/temperature limit values. The paper successfully associated the dialectic measurements with the results from the computer simulations, which are mainly based on energetic effects in electromagnetic applications. The experimental results are comparable with the software simulation in terms of precision. The conclusions outline the practical applications of the method for both electromagnetic shielding and microwave domain/telecommunications applications.

Pengaruh Bending Antena Mikrostrip Star-Patch Terhadap Parameter Antena Dengan Orientasi Bending Sumbu X

Microstrip antennas are used in various dimensions and shapes of microstrip antennas according to needs. In this use it allows bending of the microstrip antenna which changes the characteristics or parameters. In this research a microstrip antenna is designed with 24 star and 12 star patches and a staircase-shaped ground plane working at a frequency of 2.4 GHz. Design and simulation were carried out on the CST Studio Suite 2018 software and measurements were carried out with the ARINTS VNA. The simulation results show that bending causes yield degradation in the microstrip antenna parameters which include Return Loss, VSWR, Gain, Directivity, and Efficiency. the measurement results show that there is degradation in the Return Loss, VSWR, and Gain parameters. the smaller the bending radius that is done so that the antenna bends more, the performance quality value of the antenna parameters decreases.&#x0D;

High selectivity and compact tunable bandpass filter using YIG material

This paper presents a novel highly selectivity tunable filter with transmission zero. Yttrium iron garnet/gadolinium gallium garnet layer structures are added to the filter structure as bandstop units to achieve transmission zero. CST Studio Suite simulates and optimizes the filter structural parameters. Transmission zero and filter passband are tuned simultaneously. Skirt selectivity can be significantly increased by placing the transmission zero at the lower side of the filter passband. The parasitic response can be suppressed by about 20 dBc when the transmission zero is located on the upper side of the filter passband. With the magnetic field shifted from 3250 to 5005 Oe, the filter tuning range is 11–16 GHz with an insertion loss of about 3.5 dB. The addition of transmission zero enhances filter selectivity and provides more flexibility in suppressing interfering signals that vary in frequency or parasitic responses at specific frequencies. This method presents an approach for designing wide tuning range filters with transmission zeros.

МОДЕЛЮВАННЯ ВИКОРИСТАННЯ ПАСИВНИХ ЗАСОБІВ ІМІТАЦІЇ ДЛЯ СПОТВОРЕННЯ РАДІОЛОКАЦІЙНОЇ ІНФОРМАТИВНОЇ ОБСТАНОВКИ

A 3-D model of corner reflectors of various types and sizes was built on the basis of the analysis of the results of mathematical modeling using the CST Studio automatic decision-making system. As a result of the simulation, the numerical values of the parameters of the effective scattering area were determined, which made it possible to clarify the dependence of the relative change of the effective scattering area of corner reflectors on the shape of the rib, to confirm the hypothesis regarding the quadratic dependence of the effective scattering area on the radiation frequencies. A comparison was made with the results of calculations based on known analytical formulas, which were determined empirically to calculate the maximum effective scattering area for corner reflectors of typical configurations. For a more in-depth analysis of the simulation results, a conventional cross-section of the scattering diagram and its expansion relative to different angles of rotation were performed. A comparative analysis of the modeling results allowed us to conclude that for different observation angles, the effective scattering area of a small-angle reflector corresponds on average to the effective scattering area of a Mi-8T helicopter. It was also established that the most appropriate for simulating fighter jets are large corner reflectors with a rib size of 120 cm. At the same time, the weight of the corner reflector needs to be significantly reduced, which becomes possible when using light materials, such as foam plastic, which is pasted over with foil of the appropriate thickness. Electrodynamics’ modeling was confirmed by an experiment in an anechoic chamber. Experiments on changing the parameters of the effective scattering area of corner reflectors depending on a number of controlled factors have been chosen as the direction of further research. Keywords: modeling, passive means of imitation, radio engineering means, distortion, radar information environment.

A Compact and Low-Loss Tunable Bandpass Filter Using YIG/GGG Film Structures

A compact and low-loss magnetically tunable bandpass filter (BPF) is presented in this letter. The yttrium iron garnet/gadolinium gallium garnet (YIG/GGG) film structure is regarded as a resonator excited by a stepped terminal short-circuited stripline, and additional metal rings are plated on the other side of the RO4350 substrate. Two YIG/GGG film structures placed in parallel are directly coupled. This structure enhances the RF magnetic field, reduces filter loss, and suppresses parasitic response. The filter design and geometrical parameter optimization are first carried out using CST Studio Suite. When the magnetic field changes from 1820 to 7420 Oe, the filter is tuned from 5 to 19 GHz, with a 3-dB bandwidth (BW) of 62–107 MHz, insertion loss (IL) of less than 2 dB, and parasitic response suppression of about 20 dB over the entire tuning range (TR).

Coaxial Beam Rotating HPM Mode Converter Using Dielectrics Plates

The incorporation of the dielectric plates to produce phase delay for propagating waves is a widely employed technique in phase shifters and mode converters. In this article, a compact dielectric plate loaded coaxial beam rotating (CBR) mode converter having high gain and co-polarized (CP) pattern has been proposed for high-power microwave (HPM) applications at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${X}$ </tex-math></inline-formula> -band. Here, the input transverse magnetic (TM), i.e., TM01 mode, is converted to CP transverse electric (TE), i.e., TE11 likeness mode. The proposed design consists of a circular waveguide (WG) loaded with 12 dielectric polytetrafluoroethylene (PTFE) plates in a radial-azimuthal direction. For 5-mm plate thickness, the proposed design yielded a reflection loss of −20.01 dB with a radiation efficiency of 98.34% and a 17.9 dB gain at 10.084 GHz. Also, the power handling capacity of the proposed structure is predicted as 3.20 GW. Furthermore, the mode conversion is verified by measuring the far-field radiation pattern. Besides, the simulation studies of the thermal behavior of the proposed design are also discussed with the aid of CST Studio Suite.

Design of a Low-Reflection Flat Lens Antenna Based on Conformal Transformation Optics

In this paper, a wideband flat lens antenna with low reflection and good performance is presented based on conformal transformation optics (CTO). Physical space optimization is applied to eliminate singular refractive index values. Furthermore, we employ the optical path rescaling method to enhance the sub-unity refractive indices and to reduce reflection. Therefore, an implementable all-dielectric isotropic medium is obtained. The final flat lens profile comprises six layers with a constant permittivity value in each layer. Simulation results of the three-dimensional structure indicate that the designed flat lens operates in a wide frequency bandwidth. The flat lens antenna has an S11 value of less than -15 dB in the frequency range of 13 to 30 GHz. The proposed lens was designed and simulated using COMSOL Multiphysics, and radiation performance results were validated using the CST Studio Suite. The simulated radiation pattern shows that the side lobe level is less than -16.5 dB in two simulation software programs, and the half-power beam width varies from 5.6° to 2.7° with increasing frequency. Moreover, the simulated antenna gain is about 28.3-35.5 dBi in the 13-30 GHz frequency range.

RF Design and Measurements of a C-Band Prototype Structure for an Ultra-High Dose-Rate Medical Linac

In this paper, we illustrate the RF design and measurements of a C-band prototype structure for an Ultra High Dose Rate medical linac. (1) Background: FLASH Radiotherapy (RT) is a revolutionary new technique for cancer cure. It releases ultra-high radiation dose rates (above 100 Gy/s) in microsecond short pulses. In order to obtain a high dose in a very short time, accelerators with high-intensity currents (the order of 100 mA peak currents) have to be developed. In this contest, Sapienza University, in collaboration with SIT-Sordina IORT Technology spa, is developing a new C-band linac to achieve the FLASH regime. (2) Methods: We performed the RF electromagnetic design of the prototype of the C band linac using CST STUDIO Suite Code and the RF low power RF test at Sapienza University of Rome. The measurements of the field in the cavity have been done with the bead-pull technique. (3) Results: This device is a nine-cell structure operating on the π/2 mode at 5.712 GHz (C-band). We report and discuss the test measurement results on a full-scale copper prototype, showing good agreement with CST RF simulations. A tuning procedure has been implemented in order to ensure proper operating frequency and to reach a field profile flatness of the order of a few percent. (4) Conclusions: The prototype of a C-band linac for FLASH applications was successfully tested with low RF power at Sapienza University. The fabrication and ad hoc tuning procedures have been optimized and discussed in the paper.