Method for impedance measurement using multiple phase shifted chirp signals

TL;DR: In this article, the authors proposed a method for measuring the impedance of a system under test using multiple, high bandwidth, short duration chirp signals having dissimilar phase to estimate impedance.

Abstract: The invention discloses a method for measuring impedance of a system under test. The method includes multiple, high bandwidth, short duration chirp signals having dissimilar phase to estimate impedance. The method includes generating at least one chirp signal for perturbing the system under test and receiving transient response signals from the system. The received signal is then processed and analyzed to compute the instantaneous amplitude ratio and instantaneous phase shift. The impedance of the system is measured as a function of the instantaneous amplitude ratio and instantaneous phase shift. The method includes dual and triple phase shifted chirp signals to obtain the impedance profile. The system may be a linear system or nonlinear system. The method may be implemented on smaller processors with relatively low computational power and measures the impedance within 3 to 7 seconds for perturbation signals of frequency ranging from 0.1 Hz to 10 kHz.