Applicability of analysis method for electromagnetic field radiated from UTP cable in the UHF band using 4-port network

Abstract

When communication signals are transmitted at high speed on balanced cable (UTP cable), signals may leak from the cable and affect the reception of wireless signals. To evaluate this effect, the radiated electromagnetic field from the balanced cable is measured by using a 4-port network at 300 MHz or less. Although this method has the advantage that it can be used to analyze line constants, it is not clear whether it can be applied in an analysis at a frequency greater than 300 MHz. In this paper, the authors investigate the applicability of this method at frequencies up to 1 GHz. As a result, they discuss a method of using a 4-port network to represent telecommunication equipment for increasing precision and a balun for simulating this equipment and also discuss the dependency of this method on the number of subdivisions of one twist of the cable. From the results of actually evaluating the radiated electromagnetic field by using a 3-meter length of UTP cable, it was apparent that this analysis method using a 4-port network was effective for obtaining the trends exhibited by the characteristics of the radiated electromagnetic field at up to 1 GHz by obtaining the 4-port network parameters of the terminal equipment parts and dividing one twist of the cable into 80 parts. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(11): 25–35, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20391