Return Loss, Reflection Coefficient and |S11|

These data are often presented incorrectly regarding positive or negative values, potentially causing confusion and erroneous performance calculations. Along with the basic information on these measurements and their usage, author Ed Wetherhold, an engineer retired from Alliant Techsystems, identified an additional reference on this subject: In 2009, Dr. Trevor S. Bird of CSIRO, Editor-in-Chief of IEEE Transactions on Antennas & Propagation, wrote an article for IEEE Antennas & Propagation Magazine on this subject. In the introduction, Dr. Bird noted.