A new common-mode voltage probe for predicting EMI from unshielded differential-pair cables

Author

Pischl, N. ; Lockwood, J. ; Ji, H. ; Villegas, M. ; Wilson, M.

Author_Institution

Bay Networks Line of Bus., Nortel Networks, Santa Clara, CA, USA

Volume

2

fYear

1999

fDate

1999

Firstpage

873

Abstract

A common-mode (CM) voltage probe for prediction of the EMI levels from unshielded differential twisted-pair cables is described. CM currents on I/O cables are primary sources of EMI in many electronic devices. Measuring the CM voltage at the I/O connectors can be an alternative to measuring CM currents. CM voltages at the RJ-45 ports were measured and correlated to the 10m E-field levels of 8 DUTs. A CM-voltage level that correspond to the EN 55022 A limit has been derived. This allows the prediction of radiated emissions based on CM voltage measurements at the connectors. This bench-tool can be instrumental in reducing the time and cost of troubleshooting EMI problems

Keywords

electromagnetic interference; measurement standards; twisted pair cables; voltage measurement; CM-voltage level; EMI prediction; EN 55022 A limit; I/O cables; I/O connectors; RJ-45 ports; bench-tool; common-mode voltage probe; electronic devices; radiated emissions; twisted-pair cables; unshielded differential-pair cables; Cables; Clamps; Current measurement; Electromagnetic interference; Impedance; Local area networks; Probes; Testing; Voltage; Working environment noise;

fLanguage

English

Publisher

ieee

Conference_Titel

Electromagnetic Compatibility, 1999 IEEE International Symposium on

Conference_Location

Seattle, WA

Print_ISBN

0-7803-5057-X

Type

conf

DOI

10.1109/ISEMC.1999.810166

Filename

810166