Experimental data for EM coupling through slots

A key factor in predicting the vulnerability of military systems to a wide variety of EM threats involves understanding the phenomenology of how the energy penetrates through back door ports of entry (POE's). The first part of this report focuses on broadband (0.1 ..-->.. 18 GHz) laboratories and measurement techniques being used in such studies. The emphasis is on coherent cw experiments because of the very great sensitivity, dynamic range, accuracy, flexibility, and data acquisition/processing capabilities of modern rf instrumentation systems. Experimental data are given for several slot/crack configurations in a metal wall; simple slots and covered slots in a thin wall, deep slots and grooved slots in a thick wall, and dielectrically loaded slots. Also included are comparisons of slotted-wall data with cavity-backed slotted-wall data. Limited comparisons are made with experimental and analysis/numerically modeled data. Attention is focused near and above the frequency ranges where the slots are resonant. Explanations of the associated coupling phenomenologies are given for each case.