Measurement of Nonlinear Scattering of Baseband Pulsed Electromagnetic Waves by Small-Sized Objects

Abstract

A setup that allows for measuring the scattering of a step ultra-wideband electromagnetic wave (subnanosecond front duration) by small-size objects is considered. The main feature of the setup is the selection of the nonlinear response component in a scattered signal with a continuous spectrum. The intensity of the test field achieved in the experiments is 135 W/m². It is shown that the threshold sensitivity for the object’s nonlinear response is limited mainly by the shift of local fragments of the recorded signals that occurs in the stroboscopic receiver. By correcting these shifts, a threshold sensitivity for the potential of a nonlinearly scattered field of no worse than 3.5 mV was obtained at a potential of a field scattered by the object not exceeding 520 mV. The results of testing the setup using linear and nonlinear standards with known parameters, as well as observing the nonlinear response of a small-sized electronic device, are presented.