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SbD validation (LTE-2100 and LTE-3500 bands). Radiation pattern of optimized layout at a 2.045 GHz and b 3.5 GHz
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Abstract The efficient design of compact antennas operating over multiple bands suitable for the Internet of Things (IoT) is addressed by means of an instance of the system-by-design (SbD) paradigm. More specifically, an iterative strategy that combines different software modules for the search space exploration, the fast physical modeling of the r...
Citations
... The increase in the substrate height and the use of a substrate with reduced dielectric constant help in improving the bandwidth of the antenna, at the cost of increased size and cost, respectively. Compact and multiband antenna for IoT application using the system by design approach enables the fast design of an antenna [6]. Compact and multiband antennas are high in demand for IoT applications. ...
... Characteristics Mode Analysis (CMA) is an efficient tool to forecast the natural resonance for material without any feed information. The governing equations of CMA derived from the impedance metrics are described in Equations (3)- (6). ...
A four-level iterated cantor set fractal antenna for Internet of Things (IoT) applications is proposed in this work. The proposed antenna operates at 2.4 GHz and for the range of 5 GHz to 8.5 GHz. In the 5 GHz to 8.5 GHz range it covers a Wi-Fi802.11 Standard (4.9 GHz, 5 GHz, 5.9 GHz, 6 GHz), 6.56 GHz, and at the lower band it covers WiMax (2.5-2.7 GHz). The proposed antenna offers a gain up to 4 dBi with an efficiency up to 90%. The designed antenna is experimented with a partial ground plane, with and without notch to perceive its effects on S11 parameters. The antenna and its feed location is optimized for improved performance. The proposed antenna is analysed using the theory of characteristics mode analysis. The antenna is fabricated on a low-cost FR4 substrate with a dielectric constant of 4.4 anda substrate height of 1.6 mm. The antenna performance in terms of S11, VSWR, and Gain is validated by measuring the performance in an anechoic chamber with Agilent N5247A Vector Network Analyser (VNA). The antenna is designed and optimized in mentor graphics software and CST Studio. The results show good agreement between the simulated and measured performances of the antenna. The optimized geometry of the antenna is compact having overall dimensions of 32 mm×22 mm×1.6 mm and suitable for short-range IoT applications.
... The return loss and bandwidth are improved. However, it is observed that the design complexity and the limitation on the number of iterations for miniaturization lead to fabrication inaccuracies and take a lot of design time [31][32][33][34][35]. ...
... On the other hand, recent methodologies developed within the so-called Systemby-Design (SbD) framework [35], enable effective and computationally efficient integration of machine learning surrogate models with evolutionary optimizers. By means of the superior prediction capabilities of the surrogate model and solutionexploration abilities of optimizers, the SbD framework has been successfully applied for the design of complex EM devices and systems, including isotropic lenses [36], innovative radomes [37], reflectarray antennas [38], multiband antennas [39], etc. ...
Modern electromagnetic (EM) device design generally relies on extensive iterative optimizations by designers using simulation software (e.g. CST), which is a very time-consuming and tedious process. To relieve human engineers and boost productivity, we proposed a machine learning framework to solve the problem of automated design for EM tasks. The proposed approach combines advanced reinforcement learning (RL) algorithms and deep neural networks (DNNs) in an attempt to simulate the decision-making process of human designers to realize automation learning. Specifically, the RL-based agent can interact with the EM design software without engaging human designers, allowing for automated design. Besides, the data accumulated during EM software simulation in the early design stage are reused as training data to build a DNN surrogate model to replace the time-consuming EM simulation and further accelerate the training of RL to achieve better optimization of EM design. Two types of antenna array decoupling including 1×2 and 1×4 arrays working at 3.5 GHz are used as test vehicles to validate the proposed method. The decoupling metasurfaces designed by the proposed fully automated method based on RL showed satisfactory results comparable to the results achievable by human designers. This indicates that the proposed method can be used to build powerful tools to boost the design efficiency of EM devices.
... In regard to this literature reports various method to achieve multiband in an antenna like utilization of slots and slits in the radiating or ground part [6]- [9], parasitic elements [10], [11], fractals [12]- [19], stubs [20], [21] various feeding techniques [22]- [24]. Recently, the usage of metamaterial to incorporate multiband phenomenon in antenna design has gained the significant attention. ...
The present wireless applications demand a compact, multi-operated, and stable radiation pattern antenna with good gain and impedance matching performance. To accomplish this requirement. In this paper, we propose a compact metamaterial structure loaded quad band antenna. The structural specifications/layout of the antenna consists of a circular ring monopole fed by a microstrip line. The ground part of the antenna is loaded with a metamaterial rectangular split-ring resonator (RSRR), an L-shaped slot, and two horizontally placed rectangular slots parallel to each other. No external matching circuit is utilized and impedance matching is solely controlled by the placement of slots. The antenna shows operation at 2.1 GHz (2.01-2.24 GHz, a bandwidth of 230 MHz (WLAN)), 4.5 GHz (4.35-4.66 GHz, a bandwidth of 310 MHz (C-band)), 5.5 GHz (5.37-5.77 GHz bandwidth of 400 MHz (WiMAX)), and 7.2 GHz (7.08-7.33 GHz, a bandwidth of 250 MHz (satellite band)). The antenna exhibits good gain and stable radiation pattern in both the plane and thus can be utilized for aforementioned applications.
... As a matter of fact, the SbD enables an effective, reliable, and computationally-efficient use of global optimizers for addressing complex EM design problems, since it is aimed at the "task-oriented design, definition, and integration of system components to yield EM devices with user-desired performance having the minim costs, the maximum scalability, and suitable reconfigurability properties". Applications of the SbD to the synthesis of innovative meta-materials [27]- [29], fractal antennas [30], electrically-large airborne radomes [31], wide angle impedance matching layers (WAIMs) [32] [33], and reflectarray antennas [34] have been recently documented. ...
The System-by-Design (SbD) is an emerging engineering framework for the optimization-driven design of complex electromagnetic (EM) devices and systems. More specifically, the computational complexity of the design problem at hand is addressed by means of a suitable selection and integration of functional blocks comprising problem-dependent and computationally-efficient modeling and analysis tools as well as reliable prediction and optimization strategies. Thanks to the suitable re-formulation of the problem at hand as an optimization one, the profitable minimum-size coding of the degrees-of-freedom (DoFs), the "smart" replacement of expensive full-wave (FW) simulators with proper surrogate models (SMs), which yield fast yet accurate predictions starting from minimum size/reduced CPU-costs training sets, a favorable "environment" for an optimal exploitation of the features of global optimization tools in sampling wide/complex/nonlinear solution spaces is built. This research summary is then aimed at (i) providing a comprehensive description of the SbD framework and of its pillar concepts and strategies, (ii) giving useful guidelines for its successful customization and application to different EM design problems characterized by different levels of computational complexity, (iii) envisaging future trends and advances in this fascinating and high-interest (because of its relevant and topical industrial and commercial implications) topic. Representative benchmarks concerned with the synthesis of complex EM systems are presented to highlight advantages and potentialities as well as current limitations of the SbD paradigm.
... integrating EA-based strategies with fast analysis tools or digital twins (DTs), generated with learning-by-examples (LBEs) techniques [43], to speed up the evaluation (i.e., the cost function computation) of each trial solution. Thanks to its effectiveness and efficiency, the SbD has been already successfully applied to many EM design problems including the synthesis of single radiators [44], wide angle impedance matching layers [45], reflectarrays [46], and meta-material devices [47], but not to ISPs. This paper is then aimed at assessing the SbD in reliably solving fully non-linear ISPs with a computational efficiency, comparable to that of DOs, towards the "holy-grail" of a global real-time optimization. ...
The computationally-efficient solution of fully non-linear microwave inverse scattering problems (ISPs) is addressed. An innovative System-by-Design (SbD) based method is proposed to enable, for the first time to the best of the authors knowledge, an effective, robust, and time-efficient exploitation of an evolutionary algorithm (EA) to perform the global minimization of the data-mismatch cost function. According to the SbD paradigm as suitably applied to ISPs, the proposed approach founds on (i) a smart re-formulation of the ISP based on the definition of a minimum-dimensionality and representative set of degrees-of-freedom (DoFs) and on (ii) the artificial-intelligence (AI)-driven integration of a customized global search technique with a digital twin (DT) predictor based on the Gaussian Process (GP) theory. Representative numerical and experimental results are provided to assess the effectiveness and the efficiency of the proposed approach also in comparison with competitive state-of-the-art inversion techniques.
... [23] proposed a novel planar circular Apollonian fractal-shaped UWB monopole antenna with band-rejection capability. In [24], the Fast design of multiband fractal antennas for NB-IoT applications by the system-by-design approach presented. In this paper, a high gain printed circular patch Apollonian Gasket fractal slot antenna has been presented for millimeterwave wireless communication requirements. ...
Fractal geometry has widely adopted in the design of various antennas for a wide variety of communications applications. The proposed antenna design based on fractal geometry of 2nd iterations Apollonian Gasket. This type of fractal can produce an antenna that is miniaturized and multiband. The proposed antenna design built using the FR-4 AS substrate with 4.4 and a loss tangent of 0.002 with a thickness of 1.2 mm. The results show that the proposed antenna offers multiband that suitable for wireless indoor environment and millimetre-wave applications with high gains and bandwidth enhancement. This antenna also gives good radiation patterns for multiband. Modelling and performance evaluation of the proposed antenna has carried out using CST Microwave Studio (CST MWS).
... In this design, the fractal geometry of radiating antenna uses an iterative circular patch with a square slot, an altered feed-line with step method, and slot-loaded semi-circular ground plane to get a wide impedance bandwidth. Salucci et al. [13] designed a multiband fractal antenna using system by system method for NB-IoT applications. A fractal antenna for multiband applications in the frequency bands of 1.86, 2.29, 3.02, and 4.50 GHz was designed by Yogamathi et al. [14]. ...
This manuscript presents the design of an antenna based on nested square shaped ring fractal geometry with circular ring elements for multi-band wireless applications. The impedance bandwidth and reflection coefficient of the antenna are improved with the design of different iterations from the 0th to 2nd. The performance parameters of the antenna like reflection coefficient, VSWR, bandwidth, bandwidth ratio, and current density are improved in the final iteration. It also achieves the enhanced bandwidth greater than 3 GHz at three resonant frequency bands and exhibits additional frequency band at 2.4 GHz. Likewise, the frequency band of designed fractal antenna shifts towards the lower end and helps in achieving the miniaturization of antenna. The proposed fractal antenna is designed and fabricated on a low-cost FR4 glass epoxy substrate and investigated using HFSS software. The proposed antenna is optimized for generating different parameters, and the last geometry is fabricated and tested. Further, these parameters are compared with the experimental results and found in good agreement with each other. Due to the multi-band behaviour and improved bandwidth, the proposed fractal antenna can be considered as a good candidate for several wireless standards.
... Being multilevel and space filling conductive curves, and repeating a motif over two or more scale sizes called iterations, these antennas owe the specific property of highest compactness. They are used to provide multi-or wideband applications which are mostly appreciated in cellular, microwave-or body centric communications [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Very good performances could be identified with various models of antennas at different frequencies simultaneously while a series of performances were targeted during their design process analyses: miniaturization, band increase, multiple resonances achievement, high reliability and reduced costs. ...
Two simple printed fractal antennas were simulated in FEKO software with the aim of observing the influence of the dielectric substrate on their total efficiency and radiation patterns. The computations were made in the frequency range (0.5-3) GHz which is of interest for various wireless communication applications. Three types of dielectrics were investigated: an affordable material, the glass-reinforced FR-4 and two high-performance composite laminates made of Poly Tetra Fluoro Ethylene filled with glass or ceramic-duroid RT5880 and RO3003. Analyses on the obtained performances took into account: a) the nature of the dielectric substrate; b) its thickness; c) its area; d) the presence of other conductive material on the substrate. For example, RO3003 at 10 mm thick provided a maximum total efficiency of 88% of the Koch-1 antenna at a maximum realized gain of 6dBi. A usable bandwidth of 320 MHz could be achieved with this configuration while conditioning that total efficiency to always exceed 45%. INTRODUCTION In 1988 Nathan Cohen created the first self-similar shapes in the form of antenna elements while his finished designs were presented in 1995, inaugurating the fractal-antenna era [1-2]. Being multilevel and space filling conductive curves, and repeating a motif over two or more scale sizes called iterations, these antennas owe the specific property of highest compactness. They are used to provide multi-or wideband applications which are mostly appreciated in cellular, microwave-or body centric communications [3-18]. Very good performances could be identified with various models of antennas at different frequencies simultaneously while a series of performances were targeted during their design process analyses: miniaturization, band increase, multiple resonances achievement, high reliability and reduced costs. Some studies were focused on certain applications optimization. In general, fractal antennas developed for various applications in ultra-and super-high frequency bands are presently under continuous development. A previous study of ours [19] focused on finding the best solution when deploying a point-to-point ultra-high frequency radio-link between two sites situated at 5.8 km distance, from the perspective of choosing the proper fractal antenna model. From six antenna models, the optimal ones have been chosen based on simulations. Present work aimed at a computational characterization of the functioning parameters of two simple fractal antennas (one-iteration) by modifying: a) the dielectric substrate material; b) the dielectric substrate thickness; c) the dielectric substrate area; d) the presence of small conductive materials on the substrate. To obtain the solutions we used the capabilities of antenna design and analysis provided by FEKO-Altair HyperWorks software. The final objective was to observe the influence other than antenna model itself on the performance of the antenna. Since the work is entirely based on simulation, present results have not yet been validated by measurements.
... The use of fractal antennas for communication in the ultra-high frequency (UHF) range is not very new [1]- [5], but the interest for these field continues due to specific needs [6]- [8]. These antennas present a complex, convoluted form, they have a self-similar structure and are specifically recognized as multi-band antennas. ...
The paper proposes the use of MATLAB simulations as a first step in identifying proper antennas to be used in specific ultra-high frequency (UHF) communication links. Giving that fractal antennas provide interesting features, we aimed at comparing a few of their significant parameters with those of a monopole antenna so as to ensure signal coverage between two real sites situated at 5.82 km distance in a mixture of urban and flat – open terrain conditions. We started from the requirements imposed to the return loss of the antenna and to the link margin, we established their desired thresholds and then computed solutions regarding which antenna type in the set provide the highest received power and on which frequency sub-bands can be successfully used. The studied fractal antenna set were from the series Koch, Koch loop and Sierpinski. The chosen radio link refers to a real situation on the map. Generally, different narrow bands were provided by each antenna regardless of its type, but still, comparing them with the monopole, better solutions could be identified.
