This paper presents a pattern synthesis method of a sizeable concentric circular ring array (CCRAA) of isotropic antennas using Evolutionary Algorithms. In this method, the array is thinned using the optimum set of binary excitations to achieve the desired highly directive pencil beam patterns with lower peak side lobe level(SLL). The half-power beam width and first null beam width is kept constant to obtain such highly directive beam patterns with lower peak SLL. This pattern is not synthesized to a particular azimuth plane rather in four different ' planes from entire azimuth planes. The isotropic elements are uniformly spaced in the concentric ring. The achieved set of optimum amplitudes are constructed with either 1 or 0 using Differential Evolutionary Algorithm(DE), Genetic Algorithm (GA), and Particle Swarm Optimization Algorithm (PSO). These excitations show the state of the elements. The elements are in “ON” state or in “OFF” state depending upon the excitation ‘1’ or ‘0’. It is also helpful to reduce the complexity of the feed networks. The excitations are also verified in the whole range (0o
{"title":"Highly Directive Array Pattern Synthesis in Different phi Planes of a Large CCRAA Using Array Thinning Technique","authors":"S. Dubey, D. Mandal, A. K. Mishra","doi":"10.7716/aem.v11i2.1828","DOIUrl":"https://doi.org/10.7716/aem.v11i2.1828","url":null,"abstract":"This paper presents a pattern synthesis method of a sizeable concentric circular ring array (CCRAA) of isotropic antennas using Evolutionary Algorithms. In this method, the array is thinned using the optimum set of binary excitations to achieve the desired highly directive pencil beam patterns with lower peak side lobe level(SLL). The half-power beam width and first null beam width is kept constant to obtain such highly directive beam patterns with lower peak SLL. This pattern is not synthesized to a particular azimuth plane rather in four different ' planes from entire azimuth planes. The isotropic elements are uniformly spaced in the concentric ring. The achieved set of optimum amplitudes are constructed with either 1 or 0 using Differential Evolutionary Algorithm(DE), Genetic Algorithm (GA), and Particle Swarm Optimization Algorithm (PSO). These excitations show the state of the elements. The elements are in “ON” state or in “OFF” state depending upon the excitation ‘1’ or ‘0’. It is also helpful to reduce the complexity of the feed networks. The excitations are also verified in the whole range (0o <phi<360o) of ' planes by selecting four phi planes arbitrarily. The outcomes established the superiority of GA and DE over PSO and also the effectiveness of the proposed method.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47543892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article presents a basic ultra-wideband circular microstrip antenna (UWB-CMSA) with partial ground resonating from 2.38 GHz to 12 GHz for handheld devices. The designed antenna covers bands for Bluetooth (2.4 GHz), LTE (2.5/2.69 GHz), WLAN (2.4/3.5/5 GHz), and WiMAX (2.5/3.5/5.5) GHz applications. Specific Absorption Rate (SAR) values of certain bands exceed a limit for UWB-CMSA. The uniplanar spiral unit cell is designed and exhibits phase reversal for 2.4 GHz, 3.5 GHz, and 5.5 GHz. EBG unit cells are placed near the feed for surface wave minimization so as to achieve a reduction in SAR. Furthermore, the EBG structure is placed on the ground plane to analyze the impact, also designs are fabricated and results are compared. Mushroom type M-shaped unit cell is designed which offers phase reversal at 2.3 GHz which is placed near feed in a similar fashion to the earlier spiral one to suppress surface waves also the structure is investigated by arranging it on the ground plane. It is evident that SAR is reduced for all the cases being inspected but for certain bands it exceeds the limit of 1.6 W/kg. A combination of two different unit cells to form a hybrid EBG structure is proposed and evaluated by placing it near the feed. SAR is curtailed by 87.05% at 5.5 GHz.
{"title":"Ultra-Wideband Circular Microstrip Antenna with Hybrid EBG for reduced SAR","authors":"M. Munde, A. Nandgaonkar, S. Deosarkar","doi":"10.7716/aem.v11i1.1688","DOIUrl":"https://doi.org/10.7716/aem.v11i1.1688","url":null,"abstract":"This article presents a basic ultra-wideband circular microstrip antenna (UWB-CMSA) with partial ground resonating from 2.38 GHz to 12 GHz for handheld devices. The designed antenna covers bands for Bluetooth (2.4 GHz), LTE (2.5/2.69 GHz), WLAN (2.4/3.5/5 GHz), and WiMAX (2.5/3.5/5.5) GHz applications. Specific Absorption Rate (SAR) values of certain bands exceed a limit for UWB-CMSA. The uniplanar spiral unit cell is designed and exhibits phase reversal for 2.4 GHz, 3.5 GHz, and 5.5 GHz. EBG unit cells are placed near the feed for surface wave minimization so as to achieve a reduction in SAR. Furthermore, the EBG structure is placed on the ground plane to analyze the impact, also designs are fabricated and results are compared. Mushroom type M-shaped unit cell is designed which offers phase reversal at 2.3 GHz which is placed near feed in a similar fashion to the earlier spiral one to suppress surface waves also the structure is investigated by arranging it on the ground plane. It is evident that SAR is reduced for all the cases being inspected but for certain bands it exceeds the limit of 1.6 W/kg. A combination of two different unit cells to form a hybrid EBG structure is proposed and evaluated by placing it near the feed. SAR is curtailed by 87.05% at 5.5 GHz.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45513469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To enhance the safety and comfort of a driver, the wireless technology is used for inter-vehicular communication (IVC). During the lane change in highways, the driver of a high speed vehicle can exploit the antenna technology using a microcontroller. Here, a 4-element Tchebyscheff phased array of microstrip antennas for IVC application is designed at millimeter wave frequency band of 60GHz. The details of this array design with feed network, its design layout and fabricated prototype are presented. Another 4-element microstrip Tchebyscheff phased array for 6GHz IVC application is designed and the measured result is compared with the simulated result.
{"title":"Design of Microstrip Tchebyscheff Phased Array Antennas for Inter-Vehicular Communication","authors":"J. S. Roy","doi":"10.7716/aem.v11i1.1909","DOIUrl":"https://doi.org/10.7716/aem.v11i1.1909","url":null,"abstract":"To enhance the safety and comfort of a driver, the wireless technology is used for inter-vehicular communication (IVC). During the lane change in highways, the driver of a high speed vehicle can exploit the antenna technology using a microcontroller. Here, a 4-element Tchebyscheff phased array of microstrip antennas for IVC application is designed at millimeter wave frequency band of 60GHz. The details of this array design with feed network, its design layout and fabricated prototype are presented. Another 4-element microstrip Tchebyscheff phased array for 6GHz IVC application is designed and the measured result is compared with the simulated result.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47587706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper outlines a novel approach to design a waveguide to microstrip Finline transition, that allows a division by three of the RF power traveling inside a rectangular waveguide. The possibility of obtaining and odd power division of microwave and millimeter wave signals with such Finline transition is completely unexplored yet harbinger of great opportunities. Starting from a 3D CAD model of the structure and continuing with Electromagnetic simulations, the obtained results completely describe a transition able to achieve an almost perfect power splitting by three. Multyphisics simulations, show an intrinsic resistance to vibrations of such transition, allowing it to be installed on aircraft or satellites modules. Thanks to this achievement a total new kind of power devices will come next, exploiting this odd power division in fact, it will be possible to realize different types of microwave amplifiers, increasing the efficiency and decreasing the occupied size. At the Author’s best knowledge it is the first time a divider by three Finline transition is reported in literature.
{"title":"An Innovative Odd-Power Divider by means of a Triple FinLine Waveguide to Microstrip Transition","authors":"S. Fantauzzi, L. Valletti, D. Passi, F. Paolo","doi":"10.7716/aem.v11i1.1742","DOIUrl":"https://doi.org/10.7716/aem.v11i1.1742","url":null,"abstract":"This paper outlines a novel approach to design a waveguide to microstrip Finline transition, that allows a division by three of the RF power traveling inside a rectangular waveguide. The possibility of obtaining and odd power division of microwave and millimeter wave signals with such Finline transition is completely unexplored yet harbinger of great opportunities. Starting from a 3D CAD model of the structure and continuing with Electromagnetic simulations, the obtained results completely describe a transition able to achieve an almost perfect power splitting by three. Multyphisics simulations, show an intrinsic resistance to vibrations of such transition, allowing it to be installed on aircraft or satellites modules. Thanks to this achievement a total new kind of power devices will come next, exploiting this odd power division in fact, it will be possible to realize different types of microwave amplifiers, increasing the efficiency and decreasing the occupied size. At the Author’s best knowledge it is the first time a divider by three Finline transition is reported in literature.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45820196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper introduces the design of a high-gain wideband microstrip patch antenna for sub-6 GHz 5G communication. The proposed antenna integrates a novel defected ground structure (DGS) for achieving the wide bandwidth. The ground plane uses a triangular strip inserted into the ground plane to improve the performance of the antenna. It also uses the reflective plate to concentrate the side lobes and minimise the production of the back lobe, thereby boosting the main lobe of the radiated signal and thus increasing the gain of the proposed antenna. The proposed antenna uses the FR-4 epoxy substrate with an inset feed technique in its design. The simulation and optimisation of the proposed antenna were carried out with CST Microwave Studio Suite. The antenna design is compact with a dimension of 28:03 23:455:35mm3 and a maximum gain and directivity of 6.21 dB and 7.56 dB respectively, with a radiation efficiency of about 80%. The proposed antenna operates from 4.921 GHz to 5.784 GHz, which covers the 4.9 GHz-5.8 GHz of the sub-6 GHz 5G communications spectrum. Fabricated and measured result of the antenna confirm simulated results.
{"title":"A High Gain Antenna with DGS for Sub-6 GHz 5G Communications","authors":"T. Olawoye, Pradeep Kumar","doi":"10.7716/aem.v11i1.1670","DOIUrl":"https://doi.org/10.7716/aem.v11i1.1670","url":null,"abstract":"This paper introduces the design of a high-gain wideband microstrip patch antenna for sub-6 GHz 5G communication. The proposed antenna integrates a novel defected ground structure (DGS) for achieving the wide bandwidth. The ground plane uses a triangular strip inserted into the ground plane to improve the performance of the antenna. It also uses the reflective plate to concentrate the side lobes and minimise the production of the back lobe, thereby boosting the main lobe of the radiated signal and thus increasing the gain of the proposed antenna. The proposed antenna uses the FR-4 epoxy substrate with an inset feed technique in its design. The simulation and optimisation of the proposed antenna were carried out with CST Microwave Studio Suite. The antenna design is compact with a dimension of 28:03 23:455:35mm3 and a maximum gain and directivity of 6.21 dB and 7.56 dB respectively, with a radiation efficiency of about 80%. The proposed antenna operates from 4.921 GHz to 5.784 GHz, which covers the 4.9 GHz-5.8 GHz of the sub-6 GHz 5G communications spectrum. Fabricated and measured result of the antenna confirm simulated results.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42721599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electromagnetic waves present very interesting features while the permittivity of the environment approaches to zero. This property known as ENZ (Epsilon Near Zero) has been analysed with the perturbation approach-asymptotic analysis method. Wave equations have been solved by space transformation instead of phasor domain solution and the results compared. Wave equation is non-dimensionalised in order to allow asymptotic series extension. Singular perturbation theory applied to the Wave Equation and second order series extension of electromagnetic waves have been done. Validity range of the perturbation method has been investigated by modifying parameters.
{"title":"Perturbation-Asymptotic Series Approach for an Electromagnetic Wave Problem in an Epsilon Near Zero (ENZ) Material","authors":"M. K. Akkaya, A. Yılmaz, M. Kuzuoglu","doi":"10.7716/aem.v11i1.1668","DOIUrl":"https://doi.org/10.7716/aem.v11i1.1668","url":null,"abstract":"Electromagnetic waves present very interesting features while the permittivity of the environment approaches to zero. This property known as ENZ (Epsilon Near Zero) has been analysed with the perturbation approach-asymptotic analysis method. Wave equations have been solved by space transformation instead of phasor domain solution and the results compared. Wave equation is non-dimensionalised in order to allow asymptotic series extension. Singular perturbation theory applied to the Wave Equation and second order series extension of electromagnetic waves have been done. Validity range of the perturbation method has been investigated by modifying parameters.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47173807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. El Bakkali, M. A. Ennasar, O. El Mrabet, R. F. García
In this paper, we report a new design of a multifunction RFID tag antenna operating in the European band (665-868.5MHz) and the North American band (902-928 MHz) separately. The multifunction behavior can be achieved by changing the position of the RFID chip. It is found that at each feeding position, the RFID tag antenna can operate separately on both bands. The characteristics of the proposed design including S-parameters, impedance and reading range pattern have been investigated using simulation software CST Microwave Studio and experimental results. Further insight into the mechanism radiation is sought through the investigation of the current density and the equivalent circuit model. The tolerance of this design on various background materials is also investigated experimentally. The measured and simulated results show good agreement, providing a simple and low-cost design.
{"title":"Design and experimental validation of a multifunction Single layer UHF-RFID Tag antenna","authors":"M. El Bakkali, M. A. Ennasar, O. El Mrabet, R. F. García","doi":"10.7716/aem.v11i1.1639","DOIUrl":"https://doi.org/10.7716/aem.v11i1.1639","url":null,"abstract":"In this paper, we report a new design of a multifunction RFID tag antenna operating in the European band (665-868.5MHz) and the North American band (902-928 MHz) separately. The multifunction behavior can be achieved by changing the position of the RFID chip. It is found that at each feeding position, the RFID tag antenna can operate separately on both bands. The characteristics of the proposed design including S-parameters, impedance and reading range pattern have been investigated using simulation software CST Microwave Studio and experimental results. Further insight into the mechanism radiation is sought through the investigation of the current density and the equivalent circuit model. The tolerance of this design on various background materials is also investigated experimentally. The measured and simulated results show good agreement, providing a simple and low-cost design.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49339503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Sambatra, Y. C. Mombo Boussougou, Lucius Ramifidisoa, Jean-Paterne Kouadio, S. Ngoho, A. Jaomiary, N. Murad
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.
{"title":"Band Pass Negative Group Delay demonstration on a VHF RLC parallel passive lumped circuit","authors":"E. Sambatra, Y. C. Mombo Boussougou, Lucius Ramifidisoa, Jean-Paterne Kouadio, S. Ngoho, A. Jaomiary, N. Murad","doi":"10.7716/aem.v11i1.1858","DOIUrl":"https://doi.org/10.7716/aem.v11i1.1858","url":null,"abstract":"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.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46064516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"Temporal Spectrum of a Scattered Electromagnetic Waves in the Conductive Collision Turbulent Magnetized Plasma","authors":"G. Jandieri, A. Ishimaru, B. Rawat, N. Tugushi","doi":"10.7716/aem.v11i1.1859","DOIUrl":"https://doi.org/10.7716/aem.v11i1.1859","url":null,"abstract":"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.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46197958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"An Effective Antenna Array Diagnosis Method via Multivalued Neural Network Inverse Modeling Approach","authors":"O. J. Famoriji, T. Shongwe","doi":"10.7716/aem.v10i3.1784","DOIUrl":"https://doi.org/10.7716/aem.v10i3.1784","url":null,"abstract":"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.","PeriodicalId":44653,"journal":{"name":"Advanced Electromagnetics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48489609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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