Pub Date : 2020-12-08DOI: 10.47037/2020.ACES.J.351007
Rowanne Steiner, D. Ung, A. Hubrechsen, Robert D. Jones, R. Wayth, M. Bentum, A. B. Smolders
─ The far-field pattern of a geometrically large and complex antenna used in low-frequency radio astronomy is computationally expensive to simulate on electromagnetic simulators, such as FEKO. For example, one station of the Square Kilometer Array, which consists of 256 log-periodic antenna elements, will take years to simulate using the full CAD model for the full operational frequency band. This paper focuses on reducing the simulation time for a single antenna element by simplifying the simulation model, thus decreasing the number of unknowns that have to be solved in a simulation. An iterative process for optimizing the simplification of such an element is described, while keeping the reflection coefficient within 1 dB absolute mean deviation of the measured data. After four iterations, the amount of unknowns to be solved, which includes the number of triangles and segments, was reduced from 29,307 to 11,991. This decreased the computation time by 86.5%, making array simulations feasible. Using the techniques described in the paper, other antenna constructions can benefit from it and be simulated more efficiently. Index Terms ─ Antenna, FEKO, optimization techniques, radio astronomy, square-kilometer array
{"title":"Optimizing Processing Time of Radio-Astronomy Antenna Simulations Using FEKO","authors":"Rowanne Steiner, D. Ung, A. Hubrechsen, Robert D. Jones, R. Wayth, M. Bentum, A. B. Smolders","doi":"10.47037/2020.ACES.J.351007","DOIUrl":"https://doi.org/10.47037/2020.ACES.J.351007","url":null,"abstract":"─ The far-field pattern of a geometrically large and complex antenna used in low-frequency radio astronomy is computationally expensive to simulate on electromagnetic simulators, such as FEKO. For example, one station of the Square Kilometer Array, which consists of 256 log-periodic antenna elements, will take years to simulate using the full CAD model for the full operational frequency band. This paper focuses on reducing the simulation time for a single antenna element by simplifying the simulation model, thus decreasing the number of unknowns that have to be solved in a simulation. An iterative process for optimizing the simplification of such an element is described, while keeping the reflection coefficient within 1 dB absolute mean deviation of the measured data. After four iterations, the amount of unknowns to be solved, which includes the number of triangles and segments, was reduced from 29,307 to 11,991. This decreased the computation time by 86.5%, making array simulations feasible. Using the techniques described in the paper, other antenna constructions can benefit from it and be simulated more efficiently. Index Terms ─ Antenna, FEKO, optimization techniques, radio astronomy, square-kilometer array","PeriodicalId":8207,"journal":{"name":"Applied Computational Electromagnetics Society Journal","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41845539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-16DOI: 10.21203/rs.3.rs-92027/v1
Shan-shan Guan, Yu Zhu, Bingxuan Du, Dong-sheng Li, Yuan Wang, Qiong Wu, Yanju Ji
The Ground-source Airborne Time-domain Electromagnetic (GATEM) system has advantages for high efficiency and complex areas such as mountainous zone. The widely used section interpretation method, ignoring the impact of flight height, which seriously affects the interpretation and imaging accuracy of shallow anomalies. The PID controller iteration downward continuation method is proposed. Based on the original continuation iteration method, the differential coefficient and integral coefficient are added. The result shows that the new method remarkably decreases the iteration number and the accuracy are verified by comparison with the numerical integration solution. The PID controller iteration downward continuation method is applied to the interpretation of GATEM data. For synthetic data, the after continuation interpretation results are closer to the true model than the z = 30 m interpretation results. The method is also applied to GATEM field data in Yangquan City, Shanxi Province, China. The interpretation performs using PID controller iteration downward continuation results in a reliable GATEM field.
{"title":"Interpretation Method of GATEM Data Based on PID Controller Iteration Downward Continuation Method ","authors":"Shan-shan Guan, Yu Zhu, Bingxuan Du, Dong-sheng Li, Yuan Wang, Qiong Wu, Yanju Ji","doi":"10.21203/rs.3.rs-92027/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-92027/v1","url":null,"abstract":"\u0000 The Ground-source Airborne Time-domain Electromagnetic (GATEM) system has advantages for high efficiency and complex areas such as mountainous zone. The widely used section interpretation method, ignoring the impact of flight height, which seriously affects the interpretation and imaging accuracy of shallow anomalies. The PID controller iteration downward continuation method is proposed. Based on the original continuation iteration method, the differential coefficient and integral coefficient are added. The result shows that the new method remarkably decreases the iteration number and the accuracy are verified by comparison with the numerical integration solution. The PID controller iteration downward continuation method is applied to the interpretation of GATEM data. For synthetic data, the after continuation interpretation results are closer to the true model than the z = 30 m interpretation results. The method is also applied to GATEM field data in Yangquan City, Shanxi Province, China. The interpretation performs using PID controller iteration downward continuation results in a reliable GATEM field.","PeriodicalId":8207,"journal":{"name":"Applied Computational Electromagnetics Society Journal","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84739495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-07DOI: 10.47037/2020.aces.j.350806
Li-Yan Chen, Weisi Zhou, Jingsong Hong, M. Amin
A compact eight-port coplanar waveguide (CPW)-fed ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna with band-notched characteristics in a small size of 54×54×0.8 mm3 is proposed in this paper. The eight-port MIMO antenna consists of four two-port MIMO antennas. For each two-port MIMO antenna, two monopole antenna elements are printed on the FR4 substrate and placed perpendicularly to each other. To increase impedance bandwidth and improve the isolation, a stub is positioned in the middle of two radiating elements. The band-notched characteristic are achieved by etching two L-shaped resonator slots on each radiating elements, respectively. The S11 reflection coefficients, coupling isolation, radiation patterns, peak gain and radiation efficiencies of the MIMO antenna are measured. The MIMO performance of the proposed antenna is analyzed and evaluated by the envelope correlation coefficient (ECC) and total active reflection coefficient (TARC).
{"title":"A Compact Eight-port CPW-fed UWB MIMO Antenna with Band-notched Characteristic","authors":"Li-Yan Chen, Weisi Zhou, Jingsong Hong, M. Amin","doi":"10.47037/2020.aces.j.350806","DOIUrl":"https://doi.org/10.47037/2020.aces.j.350806","url":null,"abstract":"A compact eight-port coplanar waveguide (CPW)-fed ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna with band-notched characteristics in a small size of 54×54×0.8 mm3 is proposed in this paper. The eight-port MIMO antenna consists of four two-port MIMO antennas. For each two-port MIMO antenna, two monopole antenna elements are printed on the FR4 substrate and placed perpendicularly to each other. To increase impedance bandwidth and improve the isolation, a stub is positioned in the middle of two radiating elements. The band-notched characteristic are achieved by etching two L-shaped resonator slots on each radiating elements, respectively. The S11 reflection coefficients, coupling isolation, radiation patterns, peak gain and radiation efficiencies of the MIMO antenna are measured. The MIMO performance of the proposed antenna is analyzed and evaluated by the envelope correlation coefficient (ECC) and total active reflection coefficient (TARC).","PeriodicalId":8207,"journal":{"name":"Applied Computational Electromagnetics Society Journal","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79622774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-03-01DOI: 10.23919/ROPACES.2018.8364206
A. V. Londersele, D. Zutter, D. Ginste
This contribution removes some doubts about the stability issues associated with the local and anisotropic use of Crank-Nicolson (CN) time integration in Finite-Difference Time-Domain (FDTD) simulations with spatial irregularities such as nonuniformity and subgridding. Due to the lack of space, only the most significant steps in the stability analysis are treated here. Intermediate steps as well as numerical examples and implementation details will be provided during the presentation.
{"title":"Provably stable local application of Crank-Nicolson time integration to the FDTD method with nonuniform gridding and subgridding","authors":"A. V. Londersele, D. Zutter, D. Ginste","doi":"10.23919/ROPACES.2018.8364206","DOIUrl":"https://doi.org/10.23919/ROPACES.2018.8364206","url":null,"abstract":"This contribution removes some doubts about the stability issues associated with the local and anisotropic use of Crank-Nicolson (CN) time integration in Finite-Difference Time-Domain (FDTD) simulations with spatial irregularities such as nonuniformity and subgridding. Due to the lack of space, only the most significant steps in the stability analysis are treated here. Intermediate steps as well as numerical examples and implementation details will be provided during the presentation.","PeriodicalId":8207,"journal":{"name":"Applied Computational Electromagnetics Society Journal","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89808840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Through-the-Earth (TTE) communication systems require minimal infrastructure to operate. Hence, they are assumed to be more survivable and more conventional than other underground mine communications systems. This survivability is a major advantage for TTE systems. In 2006, Congress passed the Mine Improvement and New Emergency Response Act (MINER Act), which requires all underground coal mines to install wireless communications systems. The intent behind this mandate is for trapped miners to be able to communicate with surface personnel after a major accident-hence, the interest in TTE communications. To determine the likelihood of establishing a TTE communication link, it would be ideal to be able to predict the apparent conductivity of the overburden above underground mines. In this paper, all 94 mine TTE measurement data collected by Bureau of Mines in the 1970s and early 1980s, are analyzed for the first time to determine the apparent conductivity of the overburden based on three different models: a homogenous half-space model, a thin sheet model, and an attenuation factor or Q-factor model. A statistical formula is proposed to estimate the apparent earth conductivity for a specific mine based on the TTE modeling results given the mine depth and signal frequency.
{"title":"Earth Conductivity Estimation from Through-the-Earth Measurements of 94 Coal Mines Using Different Electromagnetic Models.","authors":"Lincan Yan, Joseph Waynert, Carl Sunderman","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Through-the-Earth (TTE) communication systems require minimal infrastructure to operate. Hence, they are assumed to be more survivable and more conventional than other underground mine communications systems. This survivability is a major advantage for TTE systems. In 2006, Congress passed the Mine Improvement and New Emergency Response Act (MINER Act), which requires all underground coal mines to install wireless communications systems. The intent behind this mandate is for trapped miners to be able to communicate with surface personnel after a major accident-hence, the interest in TTE communications. To determine the likelihood of establishing a TTE communication link, it would be ideal to be able to predict the apparent conductivity of the overburden above underground mines. In this paper, all 94 mine TTE measurement data collected by Bureau of Mines in the 1970s and early 1980s, are analyzed for the first time to determine the apparent conductivity of the overburden based on three different models: a homogenous half-space model, a thin sheet model, and an attenuation factor or Q-factor model. A statistical formula is proposed to estimate the apparent earth conductivity for a specific mine based on the TTE modeling results given the mine depth and signal frequency.</p>","PeriodicalId":8207,"journal":{"name":"Applied Computational Electromagnetics Society Journal","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4512942/pdf/nihms703218.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34040453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to efficiently solve a stochastic finite integration technique electrokinetic formulation a recently proposed generalized spectral decomposition approach is applied. Compared to a classical polynomial chaos expansion, the proposed approach dramatically reduces the computational burden. The results are validated by comparison with those obtained with high order polynomial chaos expansion, taken as the reference solution.
{"title":"Generalized spectral decomposition approach to a stochastic finite integration technique electrokinetic formulation","authors":"L. Codecasa, L. Rienzo","doi":"10.1049/CP.2014.0171","DOIUrl":"https://doi.org/10.1049/CP.2014.0171","url":null,"abstract":"In order to efficiently solve a stochastic finite integration technique electrokinetic formulation a recently proposed generalized spectral decomposition approach is applied. Compared to a classical polynomial chaos expansion, the proposed approach dramatically reduces the computational burden. The results are validated by comparison with those obtained with high order polynomial chaos expansion, taken as the reference solution.","PeriodicalId":8207,"journal":{"name":"Applied Computational Electromagnetics Society Journal","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2014-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1049/CP.2014.0171","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57699375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.47037/2020.aces.j.360310
This paper reported a pioneering 5G multiband microstrip line fed patch antenna for IoT, wireless power transfer (WPT) and data transmission. The proposed antenna is accomplished using a triple L-arms patch antenna responsible for the multiband response. A diamond-shaped ground slot is added to control and increase the bandwidth of the resonant frequency. The antenna is designed to resonate at 10, 13, 17 and 26 GHz with 10 dB impedance bandwidths of 0.67, 0.8, 2.45 and 4.3 GHz respectively. The proposed antenna is fabricated using microstrip technology with total area of 16.5x16.5 mm2. The 5G multiband antenna has sufficient realized gain of 4.95, 5.72, 4.94 and 7.077 dB respectively. The antenna is designed and simulated using the CST Microwave Studio Suite (Computer Simulation Technology). Measurements show good agreement with simulations in all frequencies of operation.
{"title":"Multiband Triple L-Arms Patch Antenna with Diamond Slot Ground for 5G Applications","authors":"","doi":"10.47037/2020.aces.j.360310","DOIUrl":"https://doi.org/10.47037/2020.aces.j.360310","url":null,"abstract":"This paper reported a pioneering 5G multiband microstrip line fed patch antenna for IoT, wireless power transfer (WPT) and data transmission. The proposed antenna is accomplished using a triple L-arms patch antenna responsible for the multiband response. A diamond-shaped ground slot is added to control and increase the bandwidth of the resonant frequency. The antenna is designed to resonate at 10, 13, 17 and 26 GHz with 10 dB impedance bandwidths of 0.67, 0.8, 2.45 and 4.3 GHz respectively. The proposed antenna is fabricated using microstrip technology with total area of 16.5x16.5 mm2. The 5G multiband antenna has sufficient realized gain of 4.95, 5.72, 4.94 and 7.077 dB respectively. The antenna is designed and simulated using the CST Microwave Studio Suite (Computer Simulation Technology). Measurements show good agreement with simulations in all frequencies of operation.","PeriodicalId":8207,"journal":{"name":"Applied Computational Electromagnetics Society Journal","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86400332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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