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Joong-geun Rhee - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Field Uniformity characteristics in a triangular reverberation chamber with QRS diffusers
2006 17th International Zurich Symposium on Electromagnetic Compatibility, 2006Co-Authors: Eugene Rhee, Joong-geun RheeAbstract:This paper presents the Field Uniformity characteristics of a triangular reverberation chamber which can be substituted for an open area test site or an anechoic chamber to measure EMI and EMS. Three kinds of equilateral triangular reverberation chambers with the same volume are designed, and Field distributions are simulated. Field deviations of each structure using XFDTD 5, 3 of FDTD (finite difference time domain) method are simulated and compared to each other. In order to improve the previous study results on the Ik1Id Uniformity of reverberation chamber, a diffuser of QRS (quadratic residue sequence) method was added. The chamber with two 1-period diffusers on both sides shows larger test volume compared to the chamber of one 2-period diffuser on the bottom, and the Field Uniformity is also improved approximately 1 dB.
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Simulations on Field Uniformity in a triangular reverberation chamber
International Journal of RF and Microwave Computer-Aided Engineering, 2002Co-Authors: Sam-young Chung, Joong-geun Rhee, Hwang-jae RheeAbstract:This article presented the results of an electromagnetic Field analysis inside a rectangular and triangular reverberation chamber being attached to the Schroeder Quadratic Residue Diffusers (QRD). Simulation results showed that a triangular chamber, which had more mode distribution than the rectangular chamber in the defined volume, had advantages of producing improved Field Uniformity. © 2002 Wiley Periodicals, Inc. Int J RF and Microwave CAE 12: 198–205, 2002.
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An improvement of Field Uniformity of reverberation chamber by the variance of diffuser volume ratio
APMC 2001. 2001 Asia-Pacific Microwave Conference (Cat. No.01TH8577), 1Co-Authors: Jong-chel Yun, Joong-geun Rhee, Sam-young ChungAbstract:A conventional reverberation chamber has a rectangular structure including mode-stirrers or mode-tuned stirrers to obtain the Field Uniformity inside the chamber. In this paper, we used Schroeder diffusers to obtain Field Uniformity of a rectangular reverberation chamber, and Field Uniformity characteristics were investigated with the condition of diffuser volume ratio of 0.9, 1.35, and 1.8 % of the total rectangular empty volume. The Finite-Difference Time-Domain (FDTD) simulation method was used to analyze the Field homogeneous characteristics of these reverberation chambers.
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Field Uniformity characteristics of an asymmetric structure reverberation chamber by FDTD method
2001 IEEE EMC International Symposium. Symposium Record. International Symposium on Electromagnetic Compatibility (Cat. No.01CH37161), 1Co-Authors: Sam-young Chung, Joong-geun Rhee, Hwang-jae Rhee, Kwang-soon LeeAbstract:Conventional reverberation chamber has a rectangular structure including mode-stirrers or mode-tuned stirrers to obtain the Field Uniformity inside the chamber. This paper explained how to acquire the Field Uniformity in an asymmetric structure instead of conventional rectangular structure with right-angled planes. Two types of asymmetric structure were considered. One was an asymmetric reverberation chamber using a Schroeder diffuser and another was an asymmetric chamber with an oblique enclosure including fixed randomly made diffusers (RMD) at the ratio of 1, 2 and 3 % of the total empty volume. The FDTD simulation method was used to analyze the Field homogeneous characteristics of these two types of asymmetric reverberation chambers.
Sam-young Chung - One of the best experts on this subject based on the ideXlab platform.
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Simulations on Field Uniformity in a triangular reverberation chamber
International Journal of RF and Microwave Computer-Aided Engineering, 2002Co-Authors: Sam-young Chung, Joong-geun Rhee, Hwang-jae RheeAbstract:This article presented the results of an electromagnetic Field analysis inside a rectangular and triangular reverberation chamber being attached to the Schroeder Quadratic Residue Diffusers (QRD). Simulation results showed that a triangular chamber, which had more mode distribution than the rectangular chamber in the defined volume, had advantages of producing improved Field Uniformity. © 2002 Wiley Periodicals, Inc. Int J RF and Microwave CAE 12: 198–205, 2002.
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An improvement of Field Uniformity of reverberation chamber by the variance of diffuser volume ratio
APMC 2001. 2001 Asia-Pacific Microwave Conference (Cat. No.01TH8577), 1Co-Authors: Jong-chel Yun, Joong-geun Rhee, Sam-young ChungAbstract:A conventional reverberation chamber has a rectangular structure including mode-stirrers or mode-tuned stirrers to obtain the Field Uniformity inside the chamber. In this paper, we used Schroeder diffusers to obtain Field Uniformity of a rectangular reverberation chamber, and Field Uniformity characteristics were investigated with the condition of diffuser volume ratio of 0.9, 1.35, and 1.8 % of the total rectangular empty volume. The Finite-Difference Time-Domain (FDTD) simulation method was used to analyze the Field homogeneous characteristics of these reverberation chambers.
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Field Uniformity characteristics of an asymmetric structure reverberation chamber by FDTD method
2001 IEEE EMC International Symposium. Symposium Record. International Symposium on Electromagnetic Compatibility (Cat. No.01CH37161), 1Co-Authors: Sam-young Chung, Joong-geun Rhee, Hwang-jae Rhee, Kwang-soon LeeAbstract:Conventional reverberation chamber has a rectangular structure including mode-stirrers or mode-tuned stirrers to obtain the Field Uniformity inside the chamber. This paper explained how to acquire the Field Uniformity in an asymmetric structure instead of conventional rectangular structure with right-angled planes. Two types of asymmetric structure were considered. One was an asymmetric reverberation chamber using a Schroeder diffuser and another was an asymmetric chamber with an oblique enclosure including fixed randomly made diffusers (RMD) at the ratio of 1, 2 and 3 % of the total empty volume. The FDTD simulation method was used to analyze the Field homogeneous characteristics of these two types of asymmetric reverberation chambers.
Eugene Rhee - One of the best experts on this subject based on the ideXlab platform.
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Advanced Electromagnetic Field Uniformity in Reverberation Chamber
Electrical Engineering, 2014Co-Authors: Eugene Rhee, Hyunchul Kim, Chunsu ParkAbstract:This paper presents the Field Uniformity characteristics in a triangular prism reverberation chamber and a rectangular reverberation chamber that can be substituted for an open area test site or an anechoic chamber to measure electromagnetic interference. To improve size problems of a stirrer that is an essential unit to generate a uniform Field in the reverberation chamber, we suggest a diffuser of Quadratic Residue Sequence method. To validate the substitution of a diffuser for a stirrer, a diffuser is designed for 1-3 GHz, and five types of equilateral triangular prism reverberation chambers and three types of rectangular reverberation chambers are modeled. Afterwards, the Field distributions in these eight reverberation chambers are simulated and tested. Using XFDTD 6. 2 of finite difference time domain method, Field deviations of each structure are simulated and compared to each other. An evaluation of Field Uniformity is done by cumulative probability distribution as specified in the IEC 61000-4-21. The result shows that the Field Uniformity in the chamber is within ±6 dB tolerance and also within ±3 dB standard deviation, which means a diffuser can satisfy the requirement of international standards.
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Electric Field Uniformity Characteristic of a Reverberation Chamber with a Composite QRD
Advanced Materials Research, 2013Co-Authors: Eugene Rhee, Ji Hoon LeeAbstract:This paper presents the electric Field characteristics in a reverberation chamber which is an electromagnetic compatibility test facility that uses a stirrer to generate a uniform electric Field inside it. In this paper, a diffuser is introduced from acoustics and newly designed to overcome problems of a stirrer. To validate the effect of a diffuser, a composite quadratic residue diffuser and a reverberation chamber are modeled. Then, the Field Uniformity inside the reverberation chamber is simulated by XFDTD 6.2 simulation program. Simulation results show that the electric Field Uniformity in the reverberation chamber satisfies the international standard requirement. This shows that the composite quadratic residue diffuser can be substituted for a stirrer.
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The Field Uniformity Analysis in a Triangular Prism Reverberation Chamber with a QRD
IEICE Transactions on Communications, 2011Co-Authors: Junghoon Kim, Eugene Rhee, Hye-kwang Kim, Sung-il YangAbstract:This letter presents the Field Uniformity characteristics of a triangular prism reverberation chamber. A reverberation chamber that generally uses a stirrer to create a uniform electric Field inside is an alternative to the semi-anechoic chamber for an electromagnetic compatibility test. To overcome the size and maintenance problems of a stirrer, we propose to replace it with a Quadratic Residue Diffuser which is commonly used in acoustics. To confirm that the diffuser is a valid alternative to the stirrer, a diffuser and an equilateral triangular prism reverberation chamber are designed and fabricated for 2.3-3.0GHz operation. To investigate the Field Uniformity characteristics by varying the location of the transmitting antenna, both simulation and measurement in the triangular prism reverberation chamber were also done at its two positions, respectively. A commercial program XFDTD 6.2, engaging the finite difference time domain (FDTD), is used for simulation and a cumulative probability distribution, which the IEC 61000-4-21 recommends, is used to evaluate the Field Uniformity. Both simulation and measurement results show that the Field Uniformity in the chamber satisfies the international standard requirement of ±6dB tolerance and ±3dB standard deviation, which means that a diffuser can be substituted for a stirrer.
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Comparison of Field Uniformity characteristics in a triangular reverberation chamber with QRS diffusers
2006 17th International Zurich Symposium on Electromagnetic Compatibility, 2006Co-Authors: Eugene Rhee, Joong-geun RheeAbstract:This paper presents the Field Uniformity characteristics of a triangular reverberation chamber which can be substituted for an open area test site or an anechoic chamber to measure EMI and EMS. Three kinds of equilateral triangular reverberation chambers with the same volume are designed, and Field distributions are simulated. Field deviations of each structure using XFDTD 5, 3 of FDTD (finite difference time domain) method are simulated and compared to each other. In order to improve the previous study results on the Ik1Id Uniformity of reverberation chamber, a diffuser of QRS (quadratic residue sequence) method was added. The chamber with two 1-period diffusers on both sides shows larger test volume compared to the chamber of one 2-period diffuser on the bottom, and the Field Uniformity is also improved approximately 1 dB.
Wansoo Nah - One of the best experts on this subject based on the ideXlab platform.
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em Field Uniformity analysis of rra reverberation chamber
2020 International Conference on UK-China Emerging Technologies (UCET), 2020Co-Authors: Jawad Yousaf, Hosang Lee, Muhammad Faisal, Wansoo Nah, Han Junee, Nazmul Hasan, Jun Gyu YangAbstract:This study presents the electromagnetic (EM) Field Uniformity analysis of the Korean National Radio Research Agency (RRA) reverberation chamber (RC). The analysis is performed using the normative procedure of IEC 61000-4-2 for the estimation of the lowest usable frequency (LUF) of the RRA RC based on the Field Uniformity analysis. The triaxial electric Fields at the 8 corners of the defined working volume are measured using electric Field probes for the complete rotation of mechanical stirrer. The data is obtained for the frequency range of 80 MHz -1000 MHz with 85 frequency samples as per standard requirements through the designed data acquisition software. The stirrer step size was $7.2 {o}$ which results in 50 steps of the stirrer for one complete rotation. The post-processing of the experimental data in terms of calculation of standard deviation of measured EField data and its comparison with the defined standard deviation limit in IEC 61000-4-21 standard is performed to obtain the lowest usable frequency of the RRA reverberation chamber.
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UCET - EM Field Uniformity Analysis of RRA Reverberation Chamber
2020 International Conference on UK-China Emerging Technologies (UCET), 2020Co-Authors: Jawad Yousaf, Hosang Lee, Muhammad Faisal, Wansoo Nah, Han Junee, Nazmul Hasan, Jun Gyu YangAbstract:This study presents the electromagnetic (EM) Field Uniformity analysis of the Korean National Radio Research Agency (RRA) reverberation chamber (RC). The analysis is performed using the normative procedure of IEC 61000-4-2 for the estimation of the lowest usable frequency (LUF) of the RRA RC based on the Field Uniformity analysis. The triaxial electric Fields at the 8 corners of the defined working volume are measured using electric Field probes for the complete rotation of mechanical stirrer. The data is obtained for the frequency range of 80 MHz -1000 MHz with 85 frequency samples as per standard requirements through the designed data acquisition software. The stirrer step size was $7.2 {o}$ which results in 50 steps of the stirrer for one complete rotation. The post-processing of the experimental data in terms of calculation of standard deviation of measured EField data and its comparison with the defined standard deviation limit in IEC 61000-4-21 standard is performed to obtain the lowest usable frequency of the RRA reverberation chamber.
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Analysis of Effect of Stirrer Type on Field Uniformity in RRA Reverberation Chamber
2018Co-Authors: Jawad Yousaf, Hosang Lee, Han Junhee, Jeong Eun Kim, Muhammad Faisal, Jun Gyu Yang, Wansoo NahAbstract:This study presents an extensive analysis of the statistical variations in the Field Uniformity of Korean National Radio Research Agency (RRA) reverberation chamber (RC) for different types of stirrers. The analysis is performed for five different kinds of stirrers by simulating their full wave model in moment of method (MoM) based commercial software and comparing the results with measurements. The analysis found that Field Uniformity in RC is highly dependent on the type and geometry of stirrer being used and careful selection of the stirrer type is necessary to meet the standard requirement of Field Uniformity. The good agreement between simulation and measured results is obtained when the designed stirrer geometry matches exactly with the actual installed stirrer in RRA RC.
Jun Gyu Yang - One of the best experts on this subject based on the ideXlab platform.
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em Field Uniformity analysis of rra reverberation chamber
2020 International Conference on UK-China Emerging Technologies (UCET), 2020Co-Authors: Jawad Yousaf, Hosang Lee, Muhammad Faisal, Wansoo Nah, Han Junee, Nazmul Hasan, Jun Gyu YangAbstract:This study presents the electromagnetic (EM) Field Uniformity analysis of the Korean National Radio Research Agency (RRA) reverberation chamber (RC). The analysis is performed using the normative procedure of IEC 61000-4-2 for the estimation of the lowest usable frequency (LUF) of the RRA RC based on the Field Uniformity analysis. The triaxial electric Fields at the 8 corners of the defined working volume are measured using electric Field probes for the complete rotation of mechanical stirrer. The data is obtained for the frequency range of 80 MHz -1000 MHz with 85 frequency samples as per standard requirements through the designed data acquisition software. The stirrer step size was $7.2 {o}$ which results in 50 steps of the stirrer for one complete rotation. The post-processing of the experimental data in terms of calculation of standard deviation of measured EField data and its comparison with the defined standard deviation limit in IEC 61000-4-21 standard is performed to obtain the lowest usable frequency of the RRA reverberation chamber.
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UCET - EM Field Uniformity Analysis of RRA Reverberation Chamber
2020 International Conference on UK-China Emerging Technologies (UCET), 2020Co-Authors: Jawad Yousaf, Hosang Lee, Muhammad Faisal, Wansoo Nah, Han Junee, Nazmul Hasan, Jun Gyu YangAbstract:This study presents the electromagnetic (EM) Field Uniformity analysis of the Korean National Radio Research Agency (RRA) reverberation chamber (RC). The analysis is performed using the normative procedure of IEC 61000-4-2 for the estimation of the lowest usable frequency (LUF) of the RRA RC based on the Field Uniformity analysis. The triaxial electric Fields at the 8 corners of the defined working volume are measured using electric Field probes for the complete rotation of mechanical stirrer. The data is obtained for the frequency range of 80 MHz -1000 MHz with 85 frequency samples as per standard requirements through the designed data acquisition software. The stirrer step size was $7.2 {o}$ which results in 50 steps of the stirrer for one complete rotation. The post-processing of the experimental data in terms of calculation of standard deviation of measured EField data and its comparison with the defined standard deviation limit in IEC 61000-4-21 standard is performed to obtain the lowest usable frequency of the RRA reverberation chamber.
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Analysis of Effect of Stirrer Type on Field Uniformity in RRA Reverberation Chamber
2018Co-Authors: Jawad Yousaf, Hosang Lee, Han Junhee, Jeong Eun Kim, Muhammad Faisal, Jun Gyu Yang, Wansoo NahAbstract:This study presents an extensive analysis of the statistical variations in the Field Uniformity of Korean National Radio Research Agency (RRA) reverberation chamber (RC) for different types of stirrers. The analysis is performed for five different kinds of stirrers by simulating their full wave model in moment of method (MoM) based commercial software and comparing the results with measurements. The analysis found that Field Uniformity in RC is highly dependent on the type and geometry of stirrer being used and careful selection of the stirrer type is necessary to meet the standard requirement of Field Uniformity. The good agreement between simulation and measured results is obtained when the designed stirrer geometry matches exactly with the actual installed stirrer in RRA RC.