CST MWS Research Articles

Metamaterial-based Nano-Antenna Design of Enhanced Plasmonic Electromagnetic Properties

This work, presents a design of a nano-antenna based plasmonic materials at the frequency range from 192THz to 195THz for modern applications, including THz communication systems. The proposed antenna is constructed from the 3rd iteration of the Hilbert curve patch fed with a modified coplanar 50Ω port. The back layer of the antenna was covered with a partial ground plane defective with a metamaterial-based electromagnetic band gap (EBG) layer. The antenna shows high directivity up to 68dBi at 193.4THz with an excellent matching over the entire frequency band of interest. The proposed antenna is considered of gold conductive layer mounted on a silicon dioxide (SiO2) layer. The proposed EBG was designed as the second order of the Minkowski fractal geometry. The obtained results in terms of S11 were below -10dB for the frequency band of 3THz. These results were validated using numerical techniques based on CST MWS by invoking the time domain (TD) and frequency domain (FD) solvers. The results achieved from the considered techniques agreed very well with each other.

Analysis, design, and optimization based on genetic algorithms of a highly efficient dual-band rectenna system for radiofrequency energy-harvesting applications

This paper gives an enhanced Rectenna design that operates at dual-band [2.45 and 5.8] GHz in the ISM (Industrial, Scientific, and Medical) band and is printed on an FR4-Epoxy substrate. This Rectenna design includes two proposed sub-designs for the receiving antenna and rectifier circuit based on the microstrip technology. The first sub-design concerns the microstrip patch antenna (MPA) described by its radiating element as a pentagonal, its ground being affected by a defective ground structure technique, and its polarization manner as circular polarization. This MPA design is analyzed, designed, optimized using genetic algorithms (GAs), simulated under CST MWS (i.e., computer simulation technology microwave studio), and confirmed by another software named HFSS (high-frequency structure simulator). The second sub-design concerns the microstrip rectifier circuit (MRC) that contains an input matching network based on a coupled-line impedance transformer strategy to achieve good adaptation between MPA and MRC, voltage doubler converter using an SMS7630 Schottky diode thanks to its high sensitivity, microstrip interdigital capacitor to mitigate the intrinsic losses due to the lumped elements, harmonic rejection filter based on a stepped-impedance low-pass filter to reject the unwanted harmonics generated by the non-linear behavior of SMS7630, and the resistive load that models the consumption of the system to be fed. This MRC is analyzed, designed, optimized using GAs, and simulated under ADS (Advanced Design System). The effectiveness of the proposed MPA is proven in terms of gain equals 3.06 dBi and 4.683 dBi at 2.45 GHz and 5.8 GHz respectively, and efficiency equals 95.13 % and 96.552 % at 2.45 GHz and 5.8 GHz respectively. The proposed MRC is effective in terms of efficiency at a lower input power value of about 97.18 % and 67.93 % at 2.45 GHz and 5.8 GHz respectively.

Development and Analysis of a Highly Compact Microstrip Patch Antenna for WiFi 6E Applications

In this research article, a microstrip patch antenna optimized for WiFi 6E applications is presented and analyzed. The antenna, constructed with an FR4 substrate measuring 20 × 24 × 1.53 mm³, adopts a rectangular shape and is designed using CST MWS® software. An equivalent circuit model is formulated and simulated with ADS software to ensure accurate representation. Operating at 6 GHz, simulated results from CST MWS® software indicate a bandwidth of 343 MHz (5.861 GHz to 6.204 GHz), while ADS software suggests 339 MHz (5.848 GHz to 6.187 GHz). In contrast, measured results exhibit a bandwidth of 196 MHz (5.827 GHz to 6.023 GHz). Despite slight discrepancies, satisfactory alignment is observed between computational and experimental outcomes, supported by the equivalent circuit model. Radiation patterns, gain, and efficiency are measured in an anechoic chamber and compared with simulations. E-plane shows directionality, while H-plane demonstrates omnidirectionality, aligning well with simulated patterns. The simulated gain is 5.77 dBi, measured gain is 5.61 dBi, resulting in a simulated efficiency of 93% and a measured efficiency of 88%. The antenna is deemed suitable for cost-effective WiFi 6E applications.

Analysis of Reader Orientation on Detection Performance of Hilbert Curve-based Fractal Chipless RFID Tags

The role of the orientation of the radio frequency identification (RFID) reader is vital in the RFID-based communication system. This study presents the design and analysis of the impact of the orientation of the RFID reader (angle of incidence of the plane wave) on the detection and sensitivity characteristics of fractal chipless RFID tags. Four fractal (irregular) shaped tags are developed using four iterations of the Hilbert curve filling algorithm. The full-wave EM analysis of the designed tags in Matlab is performed by exporting them in Computer Simulation Technologies Micro-Wave Studio (CST MWS) in the frequency range of 2 to 20 GHz. Firstly, the performance of the tags is analyzed by observing the radar cross-section (RCS) of the tag for the fixed orientation of the incident plane wave in three different polarizations (horizontal, vertical, and oblique). Later, the variations in the EM spectrum (RCS results) are analyzed for oblique polarization by varying the incidence plane wave in both elevations (for two cases of 0∘ and 90∘) and azimuth planes (sweeping from 0∘ to 180∘ with a step size of 10∘). The analysis of the proposed aggregated RCS response for all cases in oblique polarization produces higher coding capacity (169 bits), coding spatial capacity (16.504 bits/cm2), coding spectral capacity (9.826 bits/GHz), and coding density (0.960 bits/GHz/cm2) for the realized highly irregular tag using fourth-iteration (4T) of Hilbert curve filling algorithm. The proposed procedure of detection based on aggregated response makes the developed RFID communication system more secure and reliable.

A hollow carbonized kapok fiber/nano CoFe2O4 composite for broad bandwidth and enhanced microwave absorber

The development of intelligent and portable electrics necessitates the creation of an enhanced electromagnetic absorption and broad bandwidth microwave absorber. The synthesis of nano cobalt ferrite (CoFe2O4; CFO) combined with hollow carbonized kapok fiber by the Sol-Gel method and annealing process is a promising approach. The microwave absorption of carbonized kapok fiber/CFO was enhanced, and the bandwidth broadened due to the dielectric loss microwave absorber carbonized kapok fiber synergizing with the magnetic loss microwave absorber CFO. The results demonstrated that the minimal reflection loss of carbonized kapok fiber/CFO-6 was −52.2 dB at 8.56 GHz, with a thickness of 3.37 mm, and the broadest effective absorbing bandwidth was 6.2 GHz, with a thickness of 2.31 mm. The simulation results, which were obtained using the CST MWS software, exhibited a high degree of agreement with those obtained from the experimental measurements. The strategy offers a prospective method for the preparation of enhanced absorption and broad bandwidth microwave absorbers.

High Gain Defected Slots 3D Antenna Structure for Millimeter Applications

The antenna is designed as a 3D structure and is made from a conductible cylindrical antenna cone. The cone structure is realized using etching of elliptical slot array on the antenna. We use a conductible circular reflector under the proposed cone and increase the gain of the antenna. The proposed antenna provides effective bandwidth from 1GHz to 30GHz, but the gain of the proposed antenna is varying between 3dBi and 15dBi in the frequency band we are interested in. Geometrical details of the antenna are optimized numerically using parametric study using CST MWS Software Package. Once the optimal design is arrived at, the results are validated with another software package using HFSS Simulation Technology. The obtained results from both software packages agree very well.

A Metasurface Based High Gain Patch Antenna for Future Multiband Wireless Communication

This paper presents a novel, compact, and high gain metasurface (MS) patch antenna. The antenna structure consists of a slotted square patch in a fractal shape, integrated with a metasurface layer stacked on Taconic RF-30 dielectric material. The individual cells are arranged periodically, creating a 5 x 5-layer configuration. The proposed antenna is designed with physical dimensions of 290 x 290 mm² and achieves a maximum gain of 13.3 dBi at a frequency of 2.2 GHz. Moreover, it achieves a satisfactory minimum reflection coefficient of -10.9 dB. The design process and analysis were performed using the CST MWS simulation software. Based on the performance results obtained from this study, the suggested antenna can be considered suitable for applications in 5G communication.

Performance Comparison of Various Substrates on a Wearable Ultra-Wideband Antenna

The substrate between the patch and ground plane of microstrip antenna plays an important role in antenna design as it dictates the linear characteristics performances of the antenna. This work focusses on the comparison between three UWB antennas fabricated on different substrate materials which are Rogers Duroid RO3003™ with a dielectric constant, εr of 3, loss tangent, tan δ of 0.010 and thickness, h of 1.52 mm; denim substrate with εr of 1.7, tan δ of 0.07 and h of 0.7 mm; and felt substrate with εr of 1.3, tan δ of 0.02 and h of 1.1 mm. From the comparison, felt substrate offers a good antenna’s performance in terms of frequency range, bandwidth, gain and efficiency followed by Rogers Duroid RO3003™ and denim substrates. The simulation results show that the frequency range of the UWB antenna with felt substrate is from 2.31 GHz to 11.74 GHz with a bandwidth of 9.43 GHz; gain, G of 5.489 dBi; and efficiency, 𝜂𝜂 (%) of 91 %. The UWB antenna fabricated on RO3003™ has a frequency range from 2.94 GHz to 12.25 GHz with a bandwidth of 9.28 GHz, gain of 5.323 dBi and efficiency of 90%. Lastly, the antenna with denim substrate observed a frequency range from 2.67 GHz to 9.99 GHz with a bandwidth of 7.23 GHz, gain of 5.198 dBi and efficiency of 81.68%. The bending investigation are performed for each UWB antenna with different diameters (d = 50 mm, 80 mm and 100 mm) of vacuum cylinder in CST MWS® software and PVC pipes during measurement. It can be concluded from the simulated and measurement results that the performance of the antennas are not affected under bending condition and suitable to be worn on body for wearable applications.

Improved design and performance of the global rectenna system for wireless power transmission applications around 2.45 GHz

This work proposes a new conception of the global microstrip rectenna system operating around 2.45 GHz. This improved rectenna system associates a receiving antenna with a rectifier circuit. This rectenna is printed on an FR4 substrate. The proposed antenna is a 1×4 microstrip antenna patch array with pentagonal patches using the defective ground structure method and operates with circular polarization. To show the effectiveness of this array, the results obtained by the computer simulation technology microwave studio (CST MWS) software prove that this array is good in terms of high gain, high directivity, high efficiency, wideband, small volume, and well-adaptation, and all these results are confirmed by another solver high-frequency structure simulator (HFSS). The improved rectifier is a microstrip rectifier that uses an HSMS2852 Schottky diode by using a series topology. The effectiveness of this rectifier is proved by the simulation results using advanced design system (ADS) software in terms of well-matching input impedance, high efficiency, and important output direct current (DC) voltage value. The proposed rectenna system is more efficient compared with the existing works and is very appropriate for several applications of wireless power transmission to power supply electronic instruments in various fields cleanly on our planet.

Design and Analysis of Terahertz Antenna for Breast Tumor Detection

In this paper, two different types of rectangular patch antennas are designed for broadband gigahertz and terahertz applications. First, a patch antenna is modeled using PEC for gigahertz applications. Secondly, a patch antenna is modeled using graphene for terahertz applications. Without exposing the patient to ionizing radiations, malignant lesions can be detected by using the dielectric discontinuities in the tissues. The simulation results show a degraded reflection coefficient due to the use of PEC and graphene. Therefore, the reflection coefficient is above -10 dB at 33 GHz and at 2.6 THz and also VSWR is less than 2 dB in both gigahertz and terahertz. The purpose of this work is to develop a simple, low-cost miniaturized mmWave imaging antenna sensor that can be used to detection of breast tumors or cancers in women by monitoring the changes in the antenna’s S11 parameter. The time-domain solver of CST MWS software is used to evaluate the performance of the patch antennas in both gigahertz and terahertz frequency. In gigahertz we can absorb deflection in the resonant frequency within 1 GHz bandwidth and in terahertz we can absorb deflection in the resonant frequency about 0.005THz bandwidth. The antenna is capable of detecting tiny malignant tumors that size ≥1 mm inside the breast fantom. Other factors like S21,E-Field and farfield are also simulated to measure the efficiency of the antennas designed in both gigahertz and terahertz frequencies. By these results we conclude the antenna can detect tumor presence

Novel printed passive ultra high frequency radio frequency identification antenna using meander technique

<p>In this paper, a novel radio frequency identification (RFID) antenna using a meander technique associated with a slotted patch is studied for RFID applications in the ultra high frequency (UHF) band [867.5-868 MHz]. The proposed RFID antenna is designed on a Kapton substrate with dielectric constant 3.5 and loss of 0.0027. It consists of two opposite meander line antennas of 8 turns each one and interconnected to ALIEH H3 microchip associated to two slotted patch’s with a global size 105×25×0.1 mm<sup>3</sup>. The proposed RFID antenna is designed and simulated using CST MWS as an electromagnetic solver. The results of the simulation show a return loss of -22.64 dB at 868 MHz, a reading distance of around 5 m, and a simulated input impedance of the antenna are 31.72+j109.68 Ω at the operating frequency 868 MHz.</p>

Machine Learning-Based Approach for bandwidth and frequency Prediction for N77 band 5G Antenna

Yagi antennas are useful for wireless communications because of the directional gain they provide, allowing the antenna to concentrate the signal in either the transmission or reception direction. It is built on a substrate made of FR-4, this antenna has a return loss of −46.85 dB at 3.6 GHz and a bandwidth of 3.3–4.2 GHz within a −10 dB range, making it ideal for use in the n77 bands. Not only is it small, with a size of 0.642λ 0 × 0.583λ 0, but it also has a maximum gain of 7.95 dB and a maximum directivity of 8.58 dB. This study investigates several approaches to estimating the performance of an antenna. These approaches include simulation with a variety of software tools, including as CST, HFSS, and Altair Feko; curve fitting technology; and the RLC equivalent circuit model. After that, simulation with CST MWS is used to collect a large amount of data samples, and then supervised regression machine learning (ML) methods are used to determine the resonance frequency and bandwidth of the antenna. When it comes to predicting bandwidth and frequency, Random Forest Regression demonstrates an exceptional level of performance, particularly when comparing with the results produced by curve-fitting tools, neural networks, and regression machine learning models. When all of these considerations are taken into account, it is clear that the antenna is an outstanding option for the n77 band of a 5G communication system.

Circularly Polarized Metamaterial Patch Antenna Circuitry for Modern MIMO Applications

This research is an attempt to highlight that the presented antenna design is proposed for modern wireless communication systems, including 5G networks. The proposed antenna design is structured to realize a reconfigurable antenna terminal to suit smart wireless systems. Therefore, the proposed antenna is structured from twelve-unit cells of metamaterial (MTM) inclusions. For this, effectively, the proposed antenna profile is reduced to 0.21λ0, where λo is the free space wavelength at 2.45GHz, which occupies 40 × 30 mm2 equivalently. This is accomplished by using T-resonator inductors to conduct 3rd iteration Hilbert-shaped MTM inclusions. The proposed antenna is printed on a substrate to cover the frequency bands from 2.6GHz to 4.4GHz. To optimize the antenna performances, a numerical-parametric analysis based on CST MWS commercial software package formulations is invoked for this study. The suggested antenna performance is numerically evaluated for validation using the HFSS software suite. The antenna has great performance while being sufficiently small to be used with integrated electronics.

Novel broadband circularly polarized pentagonal printed antenna design for wireless power transmission applications

<p>This paper provides a new conception for a microstrip patch antenna array that operates in a circularly polarized manner for wireless power transmission (WPT) at 2.45 GHz. The proposed conception combines four pentagonal patches and the defected ground structure (DGS) method. The antenna array with a dielectric constant of 4.4 and a tangential loss of 0.025 is printed on a FR4 where its thickness is about 1.58 mm. The developed design aims to optimize the antenna array performance. Th e main contribution, to the telecommunications and WPT fields, is to achieve a maximum energy transfer with low losses, while also ensuring adequate adaptation to the excitation port. To prove the effectiveness of this design, simulation results were obtai ned using computer simulation technology microwave studio (CST MWS) software and validated by another solver high - frequency structure simulator (HFSS). Simulation results are presented and compared with those obtained using existing conceptions in the lite rature. The proposed design has proven to be very effective in achieving the intended objectives, which makes this design very good for radiofrequency (RF) energy collection and its various applications to power a variety of devices without harming our pla net.</p>

High-performance THz Metallic Axial Mode Helix Antenna with Optimised Truncated Hollow Cone Ground Plane for 6G Wireless Communication System

The Terahertz (THz) band antenna configuration operates in the 0.1–10 THz frequency range and offers a stable performance for future 6th Generation (6G) wireless communication systems. However, the available metallic axial mode helix antenna designs exhibit a peak directivity of lower than 18 dBi within 0.5–1 THz, making it inappropriate to be applied in wireless communication systems. Therefore, this study proposed a high-performance THz metallic five-turn axial mode helix antenna with an optimised truncated hollow cone ground plane for 6G wireless communication systems. Following the creation of the proposed antenna design using cost-effective copper (annealed), the truncated hollow cone ground plane of the THz axial mode helix antenna was optimised via simulation in a Computer Simulation Technology Microwave Studio (CST MWS) software and a verification of the proposed THz antenna design in Analysis System High-Frequency Structure Simulator (Ansys HFSS) software for a fair comparison. Based on the results, the proposed THz metallic axial mode helix antenna with optimised truncated hollow cone ground plane recorded an impedance bandwidth of 0.46 THz, Fractional Bandwidth (FBW) of 61.33% for |S11| ≤ -10 dB, and a maximum directivity and realised gain of 21.8 dBi and 21.5 dBi at 0.85 THz, respectively. Within the 0.5–1 THz, the proposed optimised THz antenna design achieved an outstanding performance, including an FBW of more than 50%, excellent directivity of higher than 15.8 dBi, radiation efficiency of greater than 87%, circular polarisation, and low-profile helix turns. In short, the proposed THz metallic axial mode helix antenna with optimised truncated hollow cone ground plane design is appropriate for various THz 6G wireless applications.

Modeling of a Hexagonal Microstrip Patch Antenna for Breast Cancer Detection

Abstract Breast cancer is a global problem, and it is inevitable to detect cancerous cells at early stages. In recent years, microwave imaging (MWI) technology has been widely applied in biomedical applications for its non-ionizing radiation. Therefore, in this paper, a low profile hexagonal microstrip patch antenna has been proposed for the technology to detect breast cancer. This antenna has wide operating bandwidth of 13.5 GHz (6.6 GHz ¬to 20.1 GHz), and the return loss is as low as -50.83 dB at 8 GHz. To evaluate the antenna performances, the proposed antenna has been simulated in two different simulation software like HFSS and CST MWS. The antenna has achieved a maximum gain of 8.82 dBi with a quasi-omnidirectional radiation pattern. A three-layered human body mimicking breast phantom with different dielectric properties has been designed with and without tumor mimicking tissue. The difference between the dielectric properties of the tumor and the dielectric properties of different layers of breast phantom in the presence of external radiation field can inform the existence of tumor inside the breast phantom. An array of eight elements of proposed antenna is distributed around the breast phantom to detect the tumor with a minimum radius of 2 mm. Because of the low profile and compact in size (7.9 mm×11.4 mm), the proposed antenna is suitable for multi-static MWI technology for breast cancer detection at early stage.

Engineering planar antenna using geometry arrangements for wireless communications and satellite applications

A triple-band microstrip patch antenna designed for the IEEE 802.16e WiMAX, IEEE 802.11a WLAN, C-band downlink communications, and Ku-band radar recent applications is suggested in this article. The planned antenna operates at 2.45, 6, and 14 GHz resonant frequencies. The antenna fulfilled triple-band physical characteristics covering industrial, scientific, and medical (ISM) bands between (2.1–2.8) GHz; (5.6–6.5) GHz for wireless local area network (WLAN) or ultra-wideband (UWB) services; and 12.7–16 GHz for future two-way 5G:6G either broadcasting or mobile satellite communications. To achieve better return loss performance, parametric studies are carried out using Microwave Studio (CST MWS). The proposed antenna is designed on the FR4 as a hosting medium of total size 46 × 38 × 1.6 mm3, combined with a planar transmission line (T.L.) feed and defected ground structure (DGS). The simulated antenna’s input reflection coefficient (S11) results and the far-field measurements show good agreement. The fabricated prototype achieves peak gain values of 2.8, 3.8, and 4.7 dBi, respectively, and bidirectional radiation characteristics. A comparative study with other recent publications is implemented to validate the consistency of the design.

Radio frequency designed a quadrature hybrid divider for the load-tolerant ICRF system on EAST

A quadrature power divider designed for EAST uses a metal plate and coaxial line structure and operates at frequencies ranging from 27 to 45 MHz. The key parameters for the power divider, including central frequency, transmission coefficient, and phase dependence of output ports, are obtained through radio frequency simulation by CST MWS and optimized to achieve reflection and isolation levels below −24 dB with a bandwidth of 20 MHz. The power divider is tested at low power levels, confirming its reliability, and demonstrating a ±10 degree tolerance for phase management during synthesis. With its simple structure, excellent RF performance, and water cooling capability, the power divider is an important component for improving the stability of the ion cyclotron heating system.

Metamaterial based AMC backed archimedean spiral antenna for in-vitro microwave hyperthermia of skin cancer

ABSTRACT This research article presents a study that uses microwave frequencies (ISM band) for treatment of skin cancer by heating the malignant cells on skin with a Microwave Hyperthermia (MWHT) applicator. The proposed MWHT applicator has been designed as an Archimedean Spiral Microstrip Patch Antenna (AMSPA) of dimensions 38 × 38 × 1.64 mm3 backed with a Meshed-shaped AMC (48 × 48 × 3.27mm3) reflector, placed at an optimized distance of 12 mm from AMSPA. The proposed AMSPA is designed as a single spiral resonator and fabricated on FR-4 substrate, excited using a feed network. The proposed AMSPA shows a resonance at 2.5 GHz with an impedance BW of 260 MHz (2.37–2.63 GHz) and peak gain of 3.20 dB with a bidirectional radiation pattern. An AMC is placed at its backside that can be exploited as a phase-compensation surface to attain an in-phase profile for directive emission and improve the BW upto 470 MHz, peak gain to 6.8 dB and also enhance the front-to-back ratio of the radiating antenna with radiation efficiency of 80%. The simulated environment for hyperthermia analysis is set up using penne’s Bio-Heat equations to deliver microwave energy to the bio-mimic, that leads to a rise in temperature over the designed bio-mimic in CST MWS in the range of 41–45°C. The validation of MWHT radiation properties and temperature rise inside the malignancy of phantom is carried out by fabricating the bio-mimic using gelatine, vegetable oils and glycerol. This set up enhances the penetration-depth of EM waves inside the tri-layered phantom up-to 29.5 mm with Effective Field Surface of 36 × 36 mm2 and SAR of 8 W/Kg.

Design and Performance Analysis of 28 GHz two-port MIMO Rectangular Microstrip Patch Antenna Array for 5G Applications

A rectangular microstrip patch antenna array with two ports, designed for operation in the mm-wave band at 28 GHz for 5G applications, has been developed to exhibit superior gain and efficiency. This paper introduces a 12-element array activated by a feed network utilizing a T-junction power combiner/divider. The array elements consist of rectangular patch antennas inserted throughout the structure. The designed array antenna exhibited a measured impedance bandwidth of 1.42 GHz. The simulated findings indicate that the antenna achieved a favorable impedance match, with isolation levels below -22 dB throughout the frequency range. The whole substrate board dimensions were 19.99 × 26.968 × 0.254 mm3. The array is positioned on the substrate material known as Rogers RT5880, resulting in a consistent and reliable radiation pattern. The CST MWS software is employed to model and simulate the microstrip patch array antenna. CST MWS is an electromagnetic simulator utilizing the Finite Integration in Technique (FIT) methodology to model and analyze full-wave electromagnetic phenomena accurately. The realized gain of 15 dBi has been reached for the combined array, whereas the individual arrays have a realized gain of 12.3 dBi. The calculated overall efficiency is roughly -0.5 decibels. The antenna array under consideration has demonstrated favorable multiple-input multiple-output (MIMO) capabilities, as evidenced by an envelope correlation coefficient (ECC) of less than 0.1.