METHOD FOR DETERMINING DIELECTRIC PERMITTIVITIES AND LAYER THICKNESSES IN MULTILAYER MEDIUM Russian patent published in 1995 - IPC

FIELD: measuring equipment. SUBSTANCE: method involves radiating N coherent probing signals on N frequencies in the direction of a multilayer medium at the first angle of incidence, receiving N first probing signals reflected from the multilayer medium at an angle equal to the first angle of incidence, converting the received signals into a time zone, singling out the peak time components in the time cepstrum (measuring the durations of the singled-out peak components of the first cepstrum), radiating additionally M second coherent probing signals at M frequencies towards the multilayer medium at the second angle of incidence, receiving M second probing signals reflected from the multilayer medium at an angle equal to the second angle of incidence, carrying out frequency filtering of the M second received signals, singling out the peak frequency components in the second cepstrum (frequency spectrum), measuring the frequencies of the singled-out peak components of the second cepstrum (frequency spectrum), determining the dielectric permittivities and thicknesses of layers in accordance with the design formulas on the basis of measured frequencies of the singled out peak components. EFFECT: higher efficiency. 6 dwg