Swept frequency single point excitation technique for measuring the shielding of aircraft

Abstract

A swept frequency single point excitation technique has been demonstrated which shows great promise for measuring the exterior-field to cable current transfer functions of well shielded aircraft without using special facilities. These measurements showed that good signal-to-noise ratios could be maintained when measuring currents on the cores of well shielded cables using only 15 W of power. Reproducibility of the measurements was good up to 80 or 100 MHz. Comparison of the peak current induced by an EMP simulator to the current transfer function measured using the swept frequency single point excitation technique showed that the two techniques displayed the same trends, however, there was some scatter in the data (about a factor of 2 or 3). The peak current response obtained using the EMP simulator appeared to be directly proportional to the magnitude of the current transfer function at 2.7 MHz. At 80 MHz, the peak current appeared to be proportional to the square root of transfer function.<>