On the assessment of robust active filter performance using state-space μ

This paper considers an application of the structured singular value, μ, to the robust performance of active filter circuits that are subject to real parameter component uncertainty. The focus is on the different Linear Fractional Transformations that are required for the calculation of safe upper bounds on filter performance without using conventional Monte-Carlo based frequency gridding techniques. State-space μ results are applied so that worst case maximum and minimum filter gain are separately determined using a non-probabilistic test on a static matrix. The methodology is illustrated by a typical analysis on an active Butterworth low pass filter of order 4.