Methodology for Standard Electromagnetic Field Measurements

Establishing standards for electromagnetic (EM) field measurements is a multifaceted endeavor which requires measurements made (1) in anechoic chambers, (2) at open-sites, and (3) within guided-wave structures, and the means to transfer these measurements from one situation to another. The underlying principles of these standard measurements and transfer standards fall into one of the two categories: (1) measurements and (2) theoretical modeling. In the former a parameter or a set of parameters is measured, while in the latter a parameter or set is calculated employing established physical and mathematical principles. In the following discussion, the three measurement topics and field transfer standards mentioned above will be discussed with the guided-wave structures being restricted to the TEM cell. Throughout the discussion the interplay between measured quantities and predicted (modeled) quantities will be seen. The frequencies considered here range from 10 kHz to 18 GHz (and upward) and are dependent upon the physical constraints imposed by our ability to implement an actual measurement, subject to the conditions imposed by rigorous electrodynamic theory in a given analytical model.