Advanced Electromagnetics

20/03/2023

Advanced Electromagnetics® (AEM) is peer-reviewed, Gold Open Access journal that publishes research articles as well as review articles in all areas of electromagnetics.

20/03/2023

We are excited to inform you about the article published in Advanced Electromagnetics by the prominent scholar Prof. Yahya Rahmat-Samii:
https://aemjournal.org/index.php/AEM/issue/view/47
The article titled "Wideband E-shaped Patch Antennas for Advanced Wireless Terminals" is now available online.

Advanced Electromagnetics® (AEM) is peer-reviewed, Gold Open Access journal that publishes research articles as well as review articles in all areas of electromagnetics.

18/02/2022

Band Pass Negative Group Delay demonstration on a VHF RLC parallel passive lumped circuit - This paper demonstrates the bandpass (BP) negative group delay (NGD) function on a passive RLC-parallel lumped network at Very High Frequencies (VHF). After the topological description of the RLC cell, the BP NGD analysis is introduced. The NGD circuit is modelled theoretical by means of voltage transfer function (VTF) expression. The analytical equations illustrating the BP NGD specifications as the NGD center frequency, NGD value, NGD bandwidth and the VTF attenuation are established in function of the R, L and C component parameters. A proof of concept is designed, fabricated as a SMD on printed circuit board, and measured. As expected, the different models (calculated, simulated and measured) present a BP NGD and are significantly corelated. The POC prototype (resp the calculated and simulated model), presents an NGD value of - 8 ns (resp -12 ns) and attenuation of - 10 dB (resp -8 dB) around a 225 MHz (resp 240 MHz) NGD center frequency. Uncertainties analysis (UA) of BP NGD specifications is also studied in order to show the influence of quality and tolerance of components for NGD circuit. The theoretical formulas of NGD specification UAs in function of R, L and C tolerances are derived. UAs with respect to 1%, 2% and 5% relative tolerances of R, L and C components constituting the POC designed circuit are performed.

Advanced Electromagnetics® (AEM) is peer-reviewed, Gold Open Access journal that publishes research articles as well as review articles in all areas of electromagnetics.

06/01/2022

Temporal Spectrum of a Scattered Electromagnetic Waves in the Conductive Collision Turbulent Magnetized Plasma - Using WKB method the peculiarities of the temporal spectrum of an ordinary and extraordinary electromagnetic wave scattered in a weakly randomly inhomogeneous three-dimensional nonstationary and conductive magnetized plasma are investigated. On the basis of the stochastic differential transport equation for the frequency fluctuation the broadening and the displacement of the temporal spectrum for both waves are obtained for the polar terrestrial ionosphere. These statistical characteristics contains anisotropic parameters: velocity of a plasma stream, conductivities of the ionosphere, elongated electron density irregularities are characterized by the anisotropy factor and inclination angle with respect to the geomagnetic lines of forces. The analysis of the power spectrum of the waves as a function of the propagation distance and the nondimensional frequency parameter containing the carrier frequency and characteristic temporal scale of electron density fluctuations are carried out. Analytical and numerical calculations have shown that the terrestrial conductivity and anisotropy factors exert a substantial influence on evaluation of the temporal spectrum than the inclination angle. It was found that the wave spectrum increases initially as the square root of the propagation distance, but at large distances it approaches a limiting value. Statistical moments of a scattered ordinary and extraordinary waves do not depend on an absorption sign and valid for both absorptive and active media.

Temporal Spectrum of a Scattered Electromagnetic Waves in the Conductive Collision Turbulent Magnetized Plasma Article Sidebar PDF Published: Jan 6, 2022 DOI: https://doi.org/10.7716/aem.v11i1.1859 Keywords: statistical moment temporal spectrum turbulent magnetized plasma electromagnetic wave fluctu...

27/12/2021

An Effective Antenna Array Diagnosis Method via Multivalued Neural Network Inverse Modeling Approach - Failure of element (s) in antenna arrays impair (s) symmetry and lead to unwanted distorted radiation pattern. The replacement of defective elements in aircraft antennas is a solution to the problem, but it remains a critical problem in space stations. In this paper, an antenna array diagnosis technique based on multivalued neural network (mNN) inverse modeling is proposed. Since inverse analytical input-to-output formulation is generally a challenging and important task in solving the inverse problem of array diagnosis, ANN is a compelling alternative, because it is trainable and learns from data in inverse modelling. The mNN technique proposed is an inverse modelling technique, which accommodates measurements for output model. This network takes radiation pattern samples with faults and matches it to the corresponding position or location of the faulty elements in that antenna array. In addition, we develop a new training error function, which focuses on the matching of each training sample by a value of our proposed inverse model, while the remaining values are free, and trained to match distorted radiation patterns. Thereby, mNN learns all training data by redirecting the faulty elements patterns into various values of the inverse model. Therefore, mNN is able to perform accurate array diagnosis in an automated and simpler manner.

An Effective Antenna Array Diagnosis Method via Multivalued Neural Network Inverse Modeling Approach Article Sidebar PDF Published: Dec 27, 2021 DOI: https://doi.org/10.7716/aem.v10i3.1784 Keywords: Antenna measurement, array diagnosis, mNN, fault detection, electromagnetic sensing, and inverse mode...

21/11/2021

Advanced Electromagnetics (Scopus CiteScore: 1.9) is looking for reviewers! Requirements :
• A PhD or equivalent;
• Good English skills;
• Publishing and reviewing experience;

Interested? please contact editor-in-chief Prof. Said Zouhdi at [email protected].
http://aemjournal.org

13/11/2021

CSRR-DGS Bandpass Filter Based on Half Mode Substrate Integrated Waveguide for X-Band Applications - In this paper, a half mode substrate integrated waveguide (HMSIW) bandpass filter using defected ground structure cells (DGS) is proposed. By using the periodic square CSRR resonant properties of DGS according to design requirement, an X-band band-pass filter is designed and analyzed to meet compact size, low insertion loss, and high rejection. The simulation results obtained by CST in X-band show that the proposed filter is characterized by a large transmitted bandwidth of about 1.38 GHz from 13.03 to 14.41 GHz. The higher simulated insertion loss is about −2.6 dB and the lower return loss is about −34 dB. The proposed filter size is 9.50 × 38.00 mm2 which make it a compact component. The structure is optimized using CST simulator. For the proposal validation, the simulation results is compared by HFSS. The simulation results are in good agreement for the two simulator.

CSRR-DGS Bandpass Filter Based on Half Mode Substrate Integrated Waveguide for X-Band Applications Article Sidebar PDF Published: Nov 11, 2021 DOI: https://doi.org/10.7716/aem.v10i3.1782 Keywords: Substrate integrated waveguide band-pass filter defected ground structure CSRR Main Article Content B.....

31/07/2021

In this paper, an optimization method of toroidal core-based Hybrid common-mode chokes (HCMCs) for the design of an Electromagnetic interferences (EMI) filter is proposed. A dedicated algorithm is developed using MATLAB to characterize compact HCMCs that exhibit effective CommonMode (CM) chokes with optimized leakage inductances by systematic variations in the winding patterns and geometric dimensions of their magnetic cores. It takes into consideration the physical limitations of these components as well as the constraints related to the design of EMI filters. The proposed algorithm allows through a small computational task to propose a variety of configurations for optimal HCMCs. Finite element method (FEM) simulations are conducted on the HCMCs to extract their CM and leakage inductances. The results are compared with those calculated analytically and yield a good match. The performances of optimized HCMCs are evaluated through their implementation in the designed filter. All the cases of HCMCs including the smallest one allow the EMI filter to easily qualify a power converter to an electromagnetic compatibility (EMC) standard.

A Hybrid Common Mode Choke Optimization Method for Input Line EMI Filter Design Article Sidebar PDF Published: Jul 31, 2021 DOI: https://doi.org/10.7716/aem.v10i2.1677 Keywords: Electromagnetic interferences filter EMI Hybrid common mode choke HCMC Optimization algorithm Main Article Content S. Khel...

31/07/2021

In this article we carry out the comparative analysis of new compact satellite polarisers based on a square guide with diaphragms. The main electromagnetic parameters of the developed microwave guide devices with various amount of diaphragms were obtained within the satellite frequency interval from 10.7 GHz to 12.75 GHz. Waveguide polarization converters with different amount of diaphragms from 2 to 5 have been designed and optimized. The main parameters of the presented polarizer were calculated applying the numerical method of finite integration in the frequency domain. Optimization of the electromagnetic parameters of the developed waveguide devices was carried out using the software CST Microwave Studio. As a result, sizes of the device designs have been optimized for the provision of improved polarization and phase parameters. The performed analysis showed that a waveguide polarizer with five diaphragms has the best electromagnetic parameters. The developed compact polarizer with five diaphragms based on a square guide provides a minimum deviation of the output phase difference from 90 degrees and high level of isolation between linear polarization over the entire operating frequency range. Presented in the article compact waveguide polarization converters can be applied in satellite systems, which require efficient polarization separation of signals.

Comparative Analysis of Compact Satellite Polarizers Based on a Guide with Diaphragms Article Sidebar PDF Published: Jul 31, 2021 DOI: https://doi.org/10.7716/aem.v10i2.1713 Keywords: waveguide polarizer diaphragms polarizer microwave devices waveguide components electromagnetic simulation transmiss...

31/07/2021

This paper presents the performance evaluation of a sleeve Balun integration in the design of a flexible loop antenna for wildlife health monitoring and tracking applications. To verify the design concept, an experimental antenna is designed, fabricated, and measured in free-space and muscle mimicking phantom. Moreover, investigations are carried out for wearable and implanted antennas in planar and conformal arrangements. In free-space, the antenna is operating within the industrial, scientific, and medical ISM 5.8 GHz band. Balun integration in the antenna design efficiently chokes the currents excited on the outer surface of the feeding cable and provides a good impedance match between antenna and feed line, as demonstrated by simulation and measurement results. On the other hand, in phantom, the antenna has a wide bandwidth characteristic that covers the most used frequency bands for in-body devices. Balun integration, in this case, showed a negligible effect on antenna’s matching properties for two studied implantation depths; 2.5 cm and 5 cm. The proposed study offers a promising guideline in the design and realization of wearable and implanted antennas.

On the Effects of Balun on Small Antennas Performance for Animal Health- Monitoring and Tracking Article Sidebar PDF Published: Jul 31, 2021 DOI: https://doi.org/10.7716/aem.v10i2.1691 Keywords: Balun coaxial fed antennas implantable antennas transmission line Main Article Content A. Alemaryeen Tafi...

31/07/2021

In this article, a frequency selective surface (FSS) based compact wideband printed antenna radiator with improved gain and directivity is proposed for sub-6 GHz 5G wireless networking applications. Due to their inherent property of possessing spatial filtering characteristics, FSSs are attracting the interest of researchers. An approach for increasing the gain and the directivity by integrating a band pass FSS on a compact built patch antenna radiator is proposed here. The architecture equations for designing the band pass FSS using double square loop geometry are defined. The printed patch antenna radiator (PAR) and a double square loop frequency selective surface (DSLFSS) are designed and integrated. The simulation results are verified using the results from the measuring setup. The output response is giving a fractional bandwith of 19.14% with 5.5 dBi gain and 6.2 dBi of directivity and thus makes it the good choice for 5G applications.

A Compact High Gain Printed Antenna with Frequency Selective Surface for 5G Wideband Applications Article Sidebar PDF Published: Jul 31, 2021 DOI: https://doi.org/10.7716/aem.v10i2.1687 Keywords: Patch Antenna Radiator (PAR), Double Square Loop Frequency Selective Surface (DSLFSS), Partial Slotted G...

31/07/2021

This paper is divided into two sections, in the first section, a new SIW and a half-mode SIW band-pass filters based on complementary hexagonal metamaterial cells (C-HMCs) are proposed. Firstly, the SIW is analyzed in case of using two C-HMC cells and in the case of using four of these cells. Secondly, the HMSIW tunable BPF is studied and optimized. The size of the half mode is reduced by almost 50%. This filter design has a very high insertion loss about -0.4 dB, and significant transmission bandwidth extending from 5.9 GHz to 6.5 GHz. In the second section of this paper, an electronically reconfigurable SIW band-pass filter is proposed. By implementing two PIN diodes in the gaps of the two C-HMC, the results of turning the diodes ON or OFF individually is a switching in the frequency center, between 5.8 GHz and 6.8 GHz. Also, a dual band with two frequency centers at (5.6 GHz and 7.4 GHz) is achieved by turning both of the diodes ON. In addition, the metamaterial properties of all the proposed filters are investigated and presented in this work.

Design of Complementary Hexagonal Metamaterial Based HMSIW Band-Pass Filter and Reconfigurable SIW Filter Using PIN Diodes Article Sidebar PDF Published: Jul 31, 2021 DOI: https://doi.org/10.7716/aem.v10i2.1596 Keywords: Band-pass filter C-HMC C-SRR metamaterials PIN diodes reconfigurability Main Ar...

30/07/2021

Antenna systems play a critical role in establishing wireless communication links and sustaining remote sensing requirements for Cubesat applications. In addition to the usual antenna design requirements, Cubesat-based spacecrafts impose additional stringent constraints related to the on-board available space, power consumption and development costs. To develop optimal antenna prototypes while considering all these constraints and decrease trial and error related costs, computational electromagnetics (CEM) simulation tools are used. The accuracy of simulation results depends to a great extent on the choice of the appropriate CEM tool for the particular antenna problem to be analyzed; ergo, identifying and answering key questions about design objectives and requirements is necessary for informed decision-making throughout the selection and design processes. However, this could be quite challenging because of existing gaps both in the practitioners’ knowledge about different CEM tools capabilities, limitations, and design know-how. This is especially true for non-specialists such as students and academics involved in student driven Cubesat projects. Therefore, the rationale of this manuscript is to bridge those gaps and clarify some common misconception commonly encountered during the selection and design processes. In that regard, first, an overview of existing antenna configurations commonly used in Cubesat communications is provided. Next, antenna design general workflow is presented. Then, capabilities and limitations of different CEM solving methods are presented. After that, CEM software selection process trade-offs and possible sources of errors are discussed from a practical viewpoint. Finally, a case study of Masat-1 antenna system design is presented as practical example.

Cubesat Antenna Analysis and Design: Are you using the right computational electromagnetic tool? Article Sidebar PDF Published: Jul 30, 2021 DOI: https://doi.org/10.7716/aem.v10i2.1517 Keywords: Antenna, CEM software, CEM solving methods, Computational electromagnetics, Cubesat, Simulation Main Arti...

10/04/2021

In this study the effects of using defected ground structures (DGS) composed of a complementary split ring resonator (CSRR) and CSRR with dumbbell (CSRR-D) for rectangular microstrip antennas are investigated. On this aim, two different antennas, which are Antenna B having CSRR etched DGS and Antenna C having CSRR-D etched DGS are designed and fabricated in comparison with the ordinary rectangular patch antenna, which is Antenna A. In both Antennas B and C, CSRR structures are etched in the same position of the ground planes. On the other hand, another ordinary microstrip antenna, called Antenna D, is designed at resonance frequency of Antenna C. For the characterization; resonance frequencies, voltage standing wave ratios, percentage bandwidths, gains, ka values and gain radiation patterns are investigated both in simulations and experiments. The numerical analyses show that 29.39% and 44.49% electrical size reduction (ESR) ratios are obtained for Antenna B and Antenna C, respectively in comparison to Antenna A. The experimental results verify the ESR ratios with 29.15% and 44.94%. Supporting, Antenna C promises 68.12% physical size reduction (PSR) as it is compared with Antenna D. These results reveal that Antenna C is a good alternative for DGS based microstrip electrically small antennas.

Electrical Size Reduction of Microstrip Antennas by Using Defected Ground Structures Composed of Complementary Split Ring Resonator Article Sidebar PDF Published: Apr 10, 2021 DOI: https://doi.org/10.7716/aem.v10i1.1556 Keywords: complementary split ring resonator defected ground structure electrica...

10/04/2021

In the present work, a dynamic stochastic method is proposed and used for the synthesis of uniform linear antenna arrays. The proposed method combines the classical invasive weeds (IWO) and the mutation process, which makes it robust, simple and shows flexibility to be adapted. The dynamic IWO applies the mutation process in the calculation of standard deviation during the spatial dispersal process of produced seeds while keeping the mean at the parent plants. In the mutation process, if special conditions were achieved, the standard deviation would be re-initialized. This proposed method tries to achieve an optimal array pattern by acting on the relative amplitude excitation of each element in the linear array for an optimal inter-element spacing. The optimal array pattern has deep or broad nulls in some directions of interferences with low sidelobes level. The objective of the synthesis is to get amplitude excitations with low dynamic range ratio (DRR), which facilitates the design of beamforming feed network. To illustrate the robustness of the proposed method, numerical examples are presented and compared with the obtained results using bees algorithm (BA), bacterial foraging algorithm (BFA), real genetic algorithm (RGA), and the corresponding reference array pattern for each example.

A Dynamic Invasive Weeds Optimization Applied to Null Control of Linear Antenna Arrays with Constrained DRR Article Sidebar PDF Published: Apr 10, 2021 DOI: https://doi.org/10.7716/aem.v10i1.1533 Keywords: Antenna array synthesis dynamic invasive weeds optimization dynamic range ratio Main Article C...

10/04/2021

Patch antenna is a low-profile antenna that has a number of advantages, low cost, light weight,
easy to feed and their attractive radiation characteristics. For aWiMAX communication system, a microstrip patch antenna which operates at 2.76 GHz frequency band was presented in this work. The hybrid system solar cell antenna allows energy recovery as well as RF Transmission. A simulation process, withMATLAB, is used to determine the electrical power collected by the studied system as a photovoltaic cell. As a antenna, parameters such as gain, directivity, radiation pattern and radiated power were studied. Simulation results, showed a resonance frequency of the antenna at 2.76 GHz with an effective return loss of -18.64dB and a gain of 6.58dBi. Thereafter, an optical rectenna based on a solar cell antenna was proposed and studied.

Design of a Compact Solar Cell Meshed Antenna for WLAN/WIMAX Application Article Sidebar PDF Published: Apr 10, 2021 DOI: https://doi.org/10.7716/aem.v10i1.1476 Keywords: Patch antenna Solar cell RF WLAN/WiMAX Main Article Content C. Baccouch Tunis El Manar University C. Bahar Gabes University H. Sa...