Loading...
Search for:
marginal-stability
0.007 seconds
Phase plane characteristics of marginally stable fractional order systems
, Article Nonlinear Science and Complexity ; 2011 , Pages 293-301 ; 9789048198832 (ISBN) ; Haeri, M ; Tavazoei, M. S ; Sharif University of Technology
Springer Netherlands
2011
Abstract
When an integer order linear time invariant system possesses unrepeated pure imaginary poles it can generate oscillatory response which is represented by invariant closed contours in the phase plane. In linear time invariant fractional order systems with the same property, due to their special characteristics, this behavior will be more complicated and the contours would not be invariant. In this paper we will investigate the behavior of fractional order systems under such conditions
Analysis of Oscillations in Linear Fractional Order Systems
, M.Sc. Thesis Sharif University of Technology ; Tavazoei, Mohammad Saleh (Supervisor)
Abstract
This thesis studies undamped oscillations generated by marginally stable fractional order linear time invariant (LTI) systems. In this study, the concept of integral curve is developed for fractional order LTI systems. The proposed concept is obtained based on equivalent integer order linear time varying (LTV) systems. Then, an analytical approach is proposed to be used for harmonic analysis of such oscillations in marginally stable commensurate order LTI systems. Also, it is shown that the Q-semi norm of the limit sets for a trajectory of these systems can be analytically determined based on the Q-semi norm of the initial condition, where Q is a specific matrix. Moreover, this result is...
Oscillations in fractional order LTI systems: Harmonic analysis and further results
, Article Signal Processing ; Volume 93, Issue 5 , 2013 , Pages 1243-1250 ; 01651684 (ISSN) ; Tavazoei, M. S ; Sharif University of Technology
2013
Abstract
This paper studies undamped oscillations generated by marginally stable fractional order linear time invariant (LTI) systems. In this study, an analytical approach is proposed to be used for harmonic analysis of such oscillations in marginally stable commensurate order LTI systems. Also, it is shown that the Q-semi norm of the limit sets for a trajectory of these systems can be analytically determined based on the Q-semi norm of the initial condition, where Q is a specific matrix. Moreover, this result is extended to the wider class of rational order systems. Finally, some numerical examples are presented to demonstrate the use of the paper results
Minimum power Miller-compensated CMOS operational amplifiers
, Article Scientia Iranica ; Vol. 21, Issue. 6 , 2014 , pp. 2243-2249 ; e-ISSN :23453605 ; Bakhtiar, M. S ; Sharif University of Technology
Abstract
A new approach for the design of two-stage Miller-compensated CMOS op amps is presented. The paper studies the basic relations between power consumption, unitygain bandwidth, the biasing region, technology parameters, and the external capacitive load. As a result, simple and efficient design guides are provided to achieve the minimum possible power consumption for the given specifications and for short-channel devices. It is shown that the conventional design procedures do not always result in minimum power op amps. The presented results are also verified by Spectre simulations