Detection of Quasi-Static Electric Fields Radiated by Electrically Small Emitters

摘要

The purposes of this report are (a) to present the theory for near-fielddetection of quasi-static electric fields produced by electrically small emitters and (b) to demonstrate detection of these fields with linear dipole and monopole antennas. These antenna types were chosen because they respond well to electric fields and they are sufficiently portable that they could be used in a search operation where the location of the small radiator (electronic timer) is unknown. Successful detection measurements of timer electric fields were achieved at a frequency of 200 kHz with both antenna types, but the detection range falls below the theoretical prediction made from previous TEM-cell characterization of electronic timer radiation. One of the main reasons is that the background noise fields were larger than expected from published values. The unexpectedly large background noise fields required us to narrow the measurement bandwidth, hence reducing the desired signal and increasing the measurement uncertainty.