Patent ID: 7554339
Filing Date: 2009-06-30
Classification: G01N

Abstract:
1. A method of electromagnetic testing of mode stirring type for a given enclosure or cavity, comprising the steps of: providing excitation inputs at discrete frequencies stepped in small frequency steps across a frequency range of interest, wherein the small frequency steps are at least slightly larger than a resonant mode bandwidth associated with the given enclosure or cavity in order to provide statistically independent electromagnetic response measurements; and measuring electromagnetic response values to the excitation inputs for analysis of an electromagnetic response characteristic of the given enclosure or cavity, wherein the excitation inputs are stepped in small frequency steps across a stirring bandwidth selected so as to contain a statistically significant number of electromagnetic response measurement values, wherein an average field level at a given frequency is determined by averaging over the electromagnetic response measurement values obtained over the stirring bandwidth when centered on the given frequency, and further comprising the step of performing an autocorrelation check of the electromagnetic response measurement values to determine if they have a desired sample independence necessary to perform a statistical analysis on the measured data, wherein if the autocorrelation check shows that the resonant mode bandwidth was not correctly selected and the subsequent frequency step size was too small, then measuring electromagnetic response values at a larger frequency step size based on an improved estimate of the resonant mode bandwidth.