Summary: Owing to the type of non-linearities involved, the analysis and the comparison of different anti-windup compensators that are available in the literature becom difficult. Towards achieving a better understanding of the mechanisms of these anti-windup compensators, we here expose the observer property allows us to unify these anti-windup compensators. This observer property allows us to unify these anti-windup compensators as special cases of the generalized anti-windup compensator due to {\it K. Åström} and {\it B. Wittenmark} [see “Computer controlled systems. Theory and design” (Englewood Cliffs, NJ 1984)], and provides a general framework to investigate their performance.