Quality control of radioelectronic apparatus components on basis of external characteristics in frequency domain

Measurement of impedances and other external parameters at several frequencies is proposed for unambiguous identification of radioelectronic apparatus components in the process of their quality control. The validity of this method is established upon transformation of a complex quantity such as impedance into a rational fractional function and subsequent polynomial series expansion of both numerator and denominator of the latter. This transformation of a measured quantity yields a linear equation containing a certain number of nonidentical groups whose vector can be arbitrarily normalized as is necessary for parametric identification of a given circuit. As an example demonstrating this procedure, inspection is considered of a high frequency (1 MHz) amplifier on a series R235UV1 integrated circuit chip for stability of performance characteristics in time as well as during fluctuations of ambient temperature and supply voltage, under humidity and under mechanical impact. A diagnostic chart is constructed for convenient fault detection and subsequent prevention in preceding stages of the production process.