The possibility of using the fractional-rational approximation to determine the parameters of closely spaced resonances

The paper discusses the problem of determining the parameters of closely spaced resonances. The overlapping ratio was introduced for estimation of the degree of the resonance peaks overlapping and analysis of its dependence against the width and magnitude of the peaks. The dependence of the error of poles estimation against the degree of resonance peaks overlapping was examined. The limits of applicability of the method of fractional-rational approximation by continued fractions were determined for two coupled resonators.