Methodology for Standard Electromagnetic Field Measurements

Abstract

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 guidedwave 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.

An Interpolation Method to Calibrate Electromagnetic Probes in Semi-Anechoic Chambers

“…), standard field generation methods (in time and frequency domain), the alignment and assembly of the experimental setup, and the uncertainty estimation budget. Regarding the frequency domain calibration, the use of TEM cells and Anechoic chambers is recommended for the ranges 9 kHz-200 MHz and 200 MHz-40 GHz, respectively [4,5]. The measurement of power amplifier harmonics, measurement of Voltage Standing Wave Ratio (VSWR) and condition of plane wave (TEM wave) should be considered according to the standards recommendations.…”

“…In order to validate this method, it is necessary to meet the requirements established in IEEE 1309 [3] and other investigations [4][5][6][7][8][9][10][11].…”

“…In that sense, EM fields measurement results should be assured, and therefore the EM probes must be calibrated [1][2][3][4].…”

“…The conventional EM probes calibration methods are defined in terms of theoretical and experimental models of EM fields generation [4,5].…”

“…In this paper, an EM probe calibration method is proposed, in the frequency range from 80 MHz to 1 GHz inside a 3-meter SAC, taking into consideration of the recommendations of IEEE 1309 [3] and other publications [4][5][6][7][8][9][10][11]. The E-field strengths were calibrated at 2, 4, 9 and 20 V/m, and the reference probes used were the Multi Axis Monopole Probe (ETS-Lindgren HI-6105) and the Orthogonal Dipole Probe (ETS-Lindgren HI-6053).…”