Showing papers on "Nyquist plot published in 1992"
TL;DR: In this article, the Nyquist stability criterion is written in terms of microwave quantities and a convenient graphical criterion is developed to determine whether an oscillation will start up near a particular resonance frequency.
Abstract: A commonly used criterion for oscillator startup is demonstrated not to be universally valid. In order to investigate startup conditions, the Nyquist stability criterion is written in terms of microwave quantities. It is shown that widely available microwave CAD can be used to create Nyquist stability plots. Since the Nyquist criterion gives only global stability information, a convenient graphical criterion is developed to determine whether an oscillation will start up near a particular resonance frequency. >
42 citations
TL;DR: In this paper, the Hilbert-Schmidt-Hankel norm (HSH-norm) of a transfer function of a stable system is shown to be equal to the square root of the area enclosed by the oriented Nyquist diagram of the transfer function.
Abstract: It is shown that the Hilbert-Schmidt-Hankel norm (HSH-norm) of a transfer function of a stable system is equal, up to a constant factor, to the square root of the area enclosed by the oriented Nyquist diagram of the transfer function (multiplicities included) A generalization is presented for the case of systems which have no poles on the stability boundary, but otherwise have no restrictions on the pole locations >
39 citations
1 Jan 1992
TL;DR: The polymerization of 3,3' or 4,4' symmetrically disubstituted 2,2'-bithiophenes leads to polymers with a characteristic "dimeric" type of side groups distribution as mentioned in this paper.
Abstract: The polymerization of 3,3’- or 4,4’- symmetrically disubstituted 2,2’-bithiophenes leads to polymers with a characteristic”dimeric” type of side groups distribution (Scheme 1).
TL;DR: Some necessary and sufficient conditions for a class of stable transfer functions to enjoy the clockwise property are obtained and these results are used to enlarge the class of systems for which the Kalman conjecture on absolute stability of nonlinear systems holds.