The Experts below are selected from a list of 1683 Experts worldwide ranked by ideXlab platform
Hidenori Muramatsu - One of the best experts on this subject based on the ideXlab platform.
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Consideration to Terminating Condition of Mains Cable for Radiated Emission Measurement Caused by Different Disturbance Sources
IEEE Transactions on Electromagnetic Compatibility, 2020Co-Authors: Kunihiro Osabe, Shinichi Okuyama, Nobuo Kuwabara, Hidenori MuramatsuAbstract:Very high frequency (VHF)-line impedance stabilization network (VHF-LISN), which is defined as the termination device for mains cable of equipment under test to specify the input impedance of each line at the mains power supply outlet, can improve correlation between test sites that perform radiated emission measurement. Balanced and unbalanced types of VHF-LISN are currently under proposal with International Special Committee on Radio Interference (CISPR) as a device for prescribing the Terminating Condition of the power supply cable. Simulation analysis with common mode (CM)/differential mode (DM) signal sources was performed to investigate the emission characteristics with the two types of termination devices under several measurement arrangements that used two-wire and three-wire mains cables. Furthermore, to confirm the validity of the simulation analysis, measurement of a versatile comb-generator-operated by ac mains was performed under the same test arrangement and two types of termination devices. Quasi CM/DM signal from an ac-operated comb generator was injected back into the mains cable of the same comb generator. This article explains how we ascertained the radiated emission characteristics with each termination device, and provides guidance for their appropriate usage.
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impacts to measurement uncertainty of radiated emi measurement by setting Terminating Condition of ac mains cable leaving from test area
Asia-Pacific Symposium on Electromagnetic Compatibility, 2018Co-Authors: Kunihiro Osabe, Nobuo Kuwabara, Hidenori MuramatsuAbstract:This paper verifies the degree of influence that the standardization of mains cable termination Condition which is currently proposed with CISPR/SC-I gives to the Standards Compliance Uncertainty (SCU). First of all, we presumed the uncertainty value of the mains cable termination in the radiating emission measurement from the results of Round Robin Test which circulated the same EUT, the same cable termination device, and the same mains cable layout. And then, the radiating emission levels which were calculated considering with the tolerance of the termination impedance were used for presuming the measurement uncertainty when the mains cable was terminated by the device. Finally, the expanded Measurement Instrumentation Uncertainty (MIU) including the uncertainty by AC mains cable Terminating Condition was considered in calculation. From this result we have proposed this Condition shall be included to the MIU.
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effectiveness evaluation of devices for ac mains cable termination control to improve reproducibility of radiated emission measurement based on the interim results of international inter laboratory comparison
International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:Specifications for the Terminating Condition of EUT cables leaving from test area have not been specified in any standards, although it is one of the sources of poor measurement uncertainty for the radiated emission measurement. To improve the reproducibility of a radiation emission measurement among test sites, VHF-LISN is proposed to simulate artificially AC mains network as the device for specifying the termination Condition of the EUT power cable. For proposing standardization of VHF-LISN, an international inter-laboratory comparison test was proposed and it is being performed now by CISPR/SCI/WG2. Although the main purpose of the inter-laboratory comparison was to compare the result with measurement Conditions of VHF-LISN and without the device, this comparison study has been performed with also including CMAD which was already standardized to a termination Condition control device and CDNE which is currently planned to standardize, as the effectiveness evaluation of AC mains-cable termination control devices. From an intermediate result of the inter-laboratory comparison measurement, the standard deviation and the average value of data were summarized for two EUTs and five test Conditions. As a tentative conclusion, the predominance of VHF-LISN has been confirmed with the factors analysis of cause in this paper.
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Improvement of radiated emission measurement reproducibility by VHF-LISN — Interim results of international inter-laboratory comparison
2014 International Symposium on Electromagnetic Compatibility Tokyo, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the Terminating Condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode absorbing device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such device. But also we were able to presume that the effectiveness of devices to the measurement reproducibility differs with the type of EUT.
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improvement of radiated emission measurement reproducibility by vhf lisn interim results of international inter laboratory comparison
International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the Terminating Condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode absorbing device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such device. But also we were able to presume that the effectiveness of devices to the measurement reproducibility differs with the type of EUT.
Sergei A. Abramov - One of the best experts on this subject based on the ideXlab platform.
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When does Zeilberger's algorithm succeed?
Advances in Applied Mathematics, 2003Co-Authors: Sergei A. AbramovAbstract:A Terminating Condition of the well-known Zeilberger's algorithm for a given hypergeometric term T(n,k) is presented. It is shown that the only information on T(n,k) that one needs in order to determine in advance whether this algorithm will succeed is the rational function T(n,k+1)/T(n,k).
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A criterion for the applicability of Zeilberger's algorithm to rational functions
Discrete Mathematics, 2002Co-Authors: Sergei A. AbramovAbstract:We consider the applicability (or Terminating Condition) of the well-known Zeilberger's algorithm and give the complete solution to this problem for the case where the original hypergeometric term F(n,k) is a rational function. We specify a class of identifies Σk=0nF(n,k)= 0, F(n,k) ∈ C(n,k), that cannot be proven by Zeilberger's algorithm. Additionally, we give examples showing that the set of hypergeometric terms on which Zeilberger's algorithm terminates is a proper subset of the set of all hypergeometric terms, but a super-set of the set of proper terms.
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ISSAC - Applicability of Zeilberger's algorithm to hypergeometric terms
Proceedings of the 2002 international symposium on Symbolic and algebraic computation - ISSAC '02, 2002Co-Authors: Sergei A. AbramovAbstract:A Terminating Condition of the well-known Zeilberger's algorithm for a given hypergeometric term T(n, k) is presented. It is shown that the only information on T(n, k) that one needs in order to determine in advance whether this algorithm will succeed is the rational function T(n, k + 1)/T(n, k).
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Applicability of Zeilberger’s Algorithm to Rational Functions
Formal Power Series and Algebraic Combinatorics, 2000Co-Authors: Sergei A. AbramovAbstract:We consider the applicability (or Terminating Condition) of the well-known Zeilberger’s algorithm and give the complete solution to this problem for the case where the original hypergeometric term F(n, k) is a rational function. We specify a class of identities \(\sum\nolimits_{k = 0}^n {F\left( {n,k} \right) = 0} \) \(F\left( {n,k} \right) \in \mathbb{C}\left( {n,k} \right)\) that cannot be proven by Zeilberger’s algorithm. Additionally we give examples showing that the set of hypergeometric terms for which Zeilberger’s algorithm terminates is a proper subset of the set of all hypergeometric terms, but a super-set of the set of proper terms.
Shinichi Okuyama - One of the best experts on this subject based on the ideXlab platform.
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Consideration to Terminating Condition of Mains Cable for Radiated Emission Measurement Caused by Different Disturbance Sources
IEEE Transactions on Electromagnetic Compatibility, 2020Co-Authors: Kunihiro Osabe, Shinichi Okuyama, Nobuo Kuwabara, Hidenori MuramatsuAbstract:Very high frequency (VHF)-line impedance stabilization network (VHF-LISN), which is defined as the termination device for mains cable of equipment under test to specify the input impedance of each line at the mains power supply outlet, can improve correlation between test sites that perform radiated emission measurement. Balanced and unbalanced types of VHF-LISN are currently under proposal with International Special Committee on Radio Interference (CISPR) as a device for prescribing the Terminating Condition of the power supply cable. Simulation analysis with common mode (CM)/differential mode (DM) signal sources was performed to investigate the emission characteristics with the two types of termination devices under several measurement arrangements that used two-wire and three-wire mains cables. Furthermore, to confirm the validity of the simulation analysis, measurement of a versatile comb-generator-operated by ac mains was performed under the same test arrangement and two types of termination devices. Quasi CM/DM signal from an ac-operated comb generator was injected back into the mains cable of the same comb generator. This article explains how we ascertained the radiated emission characteristics with each termination device, and provides guidance for their appropriate usage.
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effectiveness evaluation of devices for ac mains cable termination control to improve reproducibility of radiated emission measurement based on the interim results of international inter laboratory comparison
International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:Specifications for the Terminating Condition of EUT cables leaving from test area have not been specified in any standards, although it is one of the sources of poor measurement uncertainty for the radiated emission measurement. To improve the reproducibility of a radiation emission measurement among test sites, VHF-LISN is proposed to simulate artificially AC mains network as the device for specifying the termination Condition of the EUT power cable. For proposing standardization of VHF-LISN, an international inter-laboratory comparison test was proposed and it is being performed now by CISPR/SCI/WG2. Although the main purpose of the inter-laboratory comparison was to compare the result with measurement Conditions of VHF-LISN and without the device, this comparison study has been performed with also including CMAD which was already standardized to a termination Condition control device and CDNE which is currently planned to standardize, as the effectiveness evaluation of AC mains-cable termination control devices. From an intermediate result of the inter-laboratory comparison measurement, the standard deviation and the average value of data were summarized for two EUTs and five test Conditions. As a tentative conclusion, the predominance of VHF-LISN has been confirmed with the factors analysis of cause in this paper.
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Improvement of radiated emission measurement reproducibility by VHF-LISN — Interim results of international inter-laboratory comparison
2014 International Symposium on Electromagnetic Compatibility Tokyo, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the Terminating Condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode absorbing device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such device. But also we were able to presume that the effectiveness of devices to the measurement reproducibility differs with the type of EUT.
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improvement of radiated emission measurement reproducibility by vhf lisn interim results of international inter laboratory comparison
International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the Terminating Condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode absorbing device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such device. But also we were able to presume that the effectiveness of devices to the measurement reproducibility differs with the type of EUT.
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Effectiveness evaluation of devices for AC mains cable termination control to improve reproducibility of radiated emission measurement - based on the interim results of international inter-laboratory comparison -
2014 International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:Specifications for the Terminating Condition of EUT cables leaving from test area have not been specified in any standards, although it is one of the sources of poor measurement uncertainty for the radiated emission measurement. To improve the reproducibility of a radiation emission measurement among test sites, VHF-LISN is proposed to simulate artificially AC mains network as the device for specifying the termination Condition of the EUT power cable. For proposing standardization of VHF-LISN, an international inter-laboratory comparison test was proposed and it is being performed now by CISPR/SCI/WG2. Although the main purpose of the inter-laboratory comparison was to compare the result with measurement Conditions of VHF-LISN and without the device, this comparison study has been performed with also including CMAD which was already standardized to a termination Condition control device and CDNE which is currently planned to standardize, as the effectiveness evaluation of AC mains-cable termination control devices. From an intermediate result of the inter-laboratory comparison measurement, the standard deviation and the average value of data were summarized for two EUTs and five test Conditions. As a tentative conclusion, the predominance of VHF-LISN has been confirmed with the factors analysis of cause in this paper.
Kunihiro Osabe - One of the best experts on this subject based on the ideXlab platform.
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Consideration to Terminating Condition of Mains Cable for Radiated Emission Measurement Caused by Different Disturbance Sources
IEEE Transactions on Electromagnetic Compatibility, 2020Co-Authors: Kunihiro Osabe, Shinichi Okuyama, Nobuo Kuwabara, Hidenori MuramatsuAbstract:Very high frequency (VHF)-line impedance stabilization network (VHF-LISN), which is defined as the termination device for mains cable of equipment under test to specify the input impedance of each line at the mains power supply outlet, can improve correlation between test sites that perform radiated emission measurement. Balanced and unbalanced types of VHF-LISN are currently under proposal with International Special Committee on Radio Interference (CISPR) as a device for prescribing the Terminating Condition of the power supply cable. Simulation analysis with common mode (CM)/differential mode (DM) signal sources was performed to investigate the emission characteristics with the two types of termination devices under several measurement arrangements that used two-wire and three-wire mains cables. Furthermore, to confirm the validity of the simulation analysis, measurement of a versatile comb-generator-operated by ac mains was performed under the same test arrangement and two types of termination devices. Quasi CM/DM signal from an ac-operated comb generator was injected back into the mains cable of the same comb generator. This article explains how we ascertained the radiated emission characteristics with each termination device, and provides guidance for their appropriate usage.
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impacts to measurement uncertainty of radiated emi measurement by setting Terminating Condition of ac mains cable leaving from test area
Asia-Pacific Symposium on Electromagnetic Compatibility, 2018Co-Authors: Kunihiro Osabe, Nobuo Kuwabara, Hidenori MuramatsuAbstract:This paper verifies the degree of influence that the standardization of mains cable termination Condition which is currently proposed with CISPR/SC-I gives to the Standards Compliance Uncertainty (SCU). First of all, we presumed the uncertainty value of the mains cable termination in the radiating emission measurement from the results of Round Robin Test which circulated the same EUT, the same cable termination device, and the same mains cable layout. And then, the radiating emission levels which were calculated considering with the tolerance of the termination impedance were used for presuming the measurement uncertainty when the mains cable was terminated by the device. Finally, the expanded Measurement Instrumentation Uncertainty (MIU) including the uncertainty by AC mains cable Terminating Condition was considered in calculation. From this result we have proposed this Condition shall be included to the MIU.
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effectiveness evaluation of devices for ac mains cable termination control to improve reproducibility of radiated emission measurement based on the interim results of international inter laboratory comparison
International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:Specifications for the Terminating Condition of EUT cables leaving from test area have not been specified in any standards, although it is one of the sources of poor measurement uncertainty for the radiated emission measurement. To improve the reproducibility of a radiation emission measurement among test sites, VHF-LISN is proposed to simulate artificially AC mains network as the device for specifying the termination Condition of the EUT power cable. For proposing standardization of VHF-LISN, an international inter-laboratory comparison test was proposed and it is being performed now by CISPR/SCI/WG2. Although the main purpose of the inter-laboratory comparison was to compare the result with measurement Conditions of VHF-LISN and without the device, this comparison study has been performed with also including CMAD which was already standardized to a termination Condition control device and CDNE which is currently planned to standardize, as the effectiveness evaluation of AC mains-cable termination control devices. From an intermediate result of the inter-laboratory comparison measurement, the standard deviation and the average value of data were summarized for two EUTs and five test Conditions. As a tentative conclusion, the predominance of VHF-LISN has been confirmed with the factors analysis of cause in this paper.
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Improvement of radiated emission measurement reproducibility by VHF-LISN — Interim results of international inter-laboratory comparison
2014 International Symposium on Electromagnetic Compatibility Tokyo, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the Terminating Condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode absorbing device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such device. But also we were able to presume that the effectiveness of devices to the measurement reproducibility differs with the type of EUT.
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improvement of radiated emission measurement reproducibility by vhf lisn interim results of international inter laboratory comparison
International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the Terminating Condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode absorbing device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such device. But also we were able to presume that the effectiveness of devices to the measurement reproducibility differs with the type of EUT.
Katsuyuki Tanakajima - One of the best experts on this subject based on the ideXlab platform.
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effectiveness evaluation of devices for ac mains cable termination control to improve reproducibility of radiated emission measurement based on the interim results of international inter laboratory comparison
International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:Specifications for the Terminating Condition of EUT cables leaving from test area have not been specified in any standards, although it is one of the sources of poor measurement uncertainty for the radiated emission measurement. To improve the reproducibility of a radiation emission measurement among test sites, VHF-LISN is proposed to simulate artificially AC mains network as the device for specifying the termination Condition of the EUT power cable. For proposing standardization of VHF-LISN, an international inter-laboratory comparison test was proposed and it is being performed now by CISPR/SCI/WG2. Although the main purpose of the inter-laboratory comparison was to compare the result with measurement Conditions of VHF-LISN and without the device, this comparison study has been performed with also including CMAD which was already standardized to a termination Condition control device and CDNE which is currently planned to standardize, as the effectiveness evaluation of AC mains-cable termination control devices. From an intermediate result of the inter-laboratory comparison measurement, the standard deviation and the average value of data were summarized for two EUTs and five test Conditions. As a tentative conclusion, the predominance of VHF-LISN has been confirmed with the factors analysis of cause in this paper.
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Improvement of radiated emission measurement reproducibility by VHF-LISN — Interim results of international inter-laboratory comparison
2014 International Symposium on Electromagnetic Compatibility Tokyo, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the Terminating Condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode absorbing device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such device. But also we were able to presume that the effectiveness of devices to the measurement reproducibility differs with the type of EUT.
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improvement of radiated emission measurement reproducibility by vhf lisn interim results of international inter laboratory comparison
International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the Terminating Condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we developed a device called very high frequency line impedance stabilization network (VHF-LISN) and investigated its effectiveness. After performing the domestic inter-laboratory comparison, we proposed an international inter-laboratory comparison program to CISPR Subcommittee I, and the proposal was accepted. For the comparison purpose, we have investigated the reproducibility also by using a common mode absorbing device (CMAD) and a versatile coupling/decoupling network of AC mains for emission testing (CDNE-M). This investigation is just in progress as a future work of CISPR SC-I WG2 until February, 2014. As a glance from an interim result, we could find that all devices are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such device. But also we were able to presume that the effectiveness of devices to the measurement reproducibility differs with the type of EUT.
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Effectiveness evaluation of devices for AC mains cable termination control to improve reproducibility of radiated emission measurement - based on the interim results of international inter-laboratory comparison -
2014 International Symposium on Electromagnetic Compatibility, 2014Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:Specifications for the Terminating Condition of EUT cables leaving from test area have not been specified in any standards, although it is one of the sources of poor measurement uncertainty for the radiated emission measurement. To improve the reproducibility of a radiation emission measurement among test sites, VHF-LISN is proposed to simulate artificially AC mains network as the device for specifying the termination Condition of the EUT power cable. For proposing standardization of VHF-LISN, an international inter-laboratory comparison test was proposed and it is being performed now by CISPR/SCI/WG2. Although the main purpose of the inter-laboratory comparison was to compare the result with measurement Conditions of VHF-LISN and without the device, this comparison study has been performed with also including CMAD which was already standardized to a termination Condition control device and CDNE which is currently planned to standardize, as the effectiveness evaluation of AC mains-cable termination control devices. From an intermediate result of the inter-laboratory comparison measurement, the standard deviation and the average value of data were summarized for two EUTs and five test Conditions. As a tentative conclusion, the predominance of VHF-LISN has been confirmed with the factors analysis of cause in this paper.
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investigation on effectiveness of very high frequency line impedance stabilization network vhf lisn for measurement reproducibility
International Symposium on Electromagnetic Compatibility, 2013Co-Authors: Shinichi Okuyama, Katsuyuki Tanakajima, Kunihiro Osabe, Hidenori MuramatsuAbstract:At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to the equipment under test (EUT) in the test site, i.e., do not define the common mode impedance as the Terminating Condition on the far end of the EUT power cable. Because of the difference in the Terminating Condition of the EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are poor in reproducibility. In an effort to resolve this issue, we investigated the effectiveness of some devices through inter-laboratory comparison measurements in which a very high frequency line impedance stabilization network (VHF-LISN) and a common mode absorbing device (CMAD), one at a time, were inserted between the mains network and the EUT power cable for the purpose of defining the Terminating Condition. As a result, we found that both VHF-LISN and CMAD are effective to improve the reproducibility of radiated emission measurement in comparison with the case of no such device, but we also found that their effectiveness differs with the type of EUT.