DocumentCode :
2888832
Title :
Multi-mode propagation on a medium frequency twin-lead transmission line with earth return
Author :
Brocker, Donovan E. ; Werner, Pingjuan L. ; Werner, Douglas H. ; Waynert, Joseph ; Jingcheng Li ; Damiano, Nicholas W.
Author_Institution :
Dept. of Electr. Eng., Pennsylvania State Univ., University Park, PA, USA
fYear :
2013
fDate :
7-13 July 2013
Firstpage :
1936
Lastpage :
1937
Abstract :
This work presents research in the development of medium frequency communications systems that the National Institute for Occupational Safety and Health (NIOSH) is performing in support of the 2006 MINER Act. In this work, a 280-m twin-lead (30-cm separation, 725-ohm) transmission line (TL) was constructed and used to measure complex input impedance and line currents resulting from open and shorted terminations at medium frequencies (MF). The line was placed in free space and positioned close to a lossy earth surface. This 3-conductor system (two wires and earth) was chosen to be a starting point to investigate the multimodal nature TLs may possess inside a coal mine. Although the TL was constructed to be physically isolated from the ground, measurements indicate the existence of common mode (CM) currents which are characteristic of a three-conductor system; hence, the ground affected the MF propagation characteristics. In this paper, full-wave computational models using moment methods are compared with the experimental measurements as a way to determine the origin of the CM currents. In the future, related experiments will be performed in underground mines in an effort to predict how multimodal MF signals will propagate in the presence of similar multiple-conductor systems.
Keywords :
coal; method of moments; mining; multiconductor transmission lines; radiowave propagation; 2006 MINER Act; NIOSH; National Institute for Occupational Safety and Health; common mode currents; full-wave computational models; lossy earth surface; medium frequency twin-lead transmission line; moment methods; multimode propagation; three-conductor system; Coal mining; Computational modeling; Conductors; Current measurement; Earth; Transmission line measurements; Wires;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Antennas and Propagation Society International Symposium (APSURSI), 2013 IEEE
Conference_Location :
Orlando, FL
ISSN :
1522-3965
Print_ISBN :
978-1-4673-5315-1
Type :
conf
DOI :
10.1109/APS.2013.6711626
Filename :
6711626
Link To Document :
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