Document Type
Article
Publication Date
4-2020
Abstract
Imperfect balancing networks (baluns) have been identified as a source of error in emission and site attenuation measurements. For this reason performance tests have been developed to characterize the symmetry of baluns. We draw a distinction between symmetry and balance as they relate to baluns and describe both quantitatively in terms of 3-port network parameters. It is shown that a symmetric balun alone does not necessarily eliminate common-mode (CM) current on the feed transmission line. Common-mode current on the feed transmission line is minimized by use of a current balun. However, for a given implementation such as a transmissionline transformer, some types of baluns are more difficult to implement than others and an imperfect, asymmetric current balun may perform worse than another type of balun (e.g. voltage) which is more symmetric. The case of a verticallypolarized biconical antenna situated over a ground plane and driven from a coaxial feed line via a balun is examined for three symmetric baluns: a voltage balun, a current balun, and a 180◦ power divider. It is shown that although all three baluns are symmetric, only the current balun maintains the dipolar pattern under the asymmetrical influence of the ground plane.
Recommended Citation
J. S. McLean and H. D. Foltz, "Symmetry Versus Balance in Balancing Networks for Dipolar Antennas," in IEEE Transactions on Electromagnetic Compatibility, vol. 62, no. 4, pp. 1406-1418, Aug. 2020, doi: 10.1109/TEMC.2020.2978445.
First Page
1406
Last Page
1418
Publication Title
IEEE Transactions on Electromagnetic Compatibility
DOI
10.1109/TEMC.2020.2978445
Comments
© 2020 IEEE - All rights reserved. Original published version available at doi.org/10.1109/TEMC.2020.2978445