Abstract: Nonlinear distortion‚one of the primary constraints in filter design and manufacture‚is due to the nonlinearity between the elementary components and the circuit units in filter topological structures．In this paper‚the nonlinearity of a typical circuit unit（Schaumann component） was investigated and the analytical equations of the nonlinearity were deduced．On the basis of which‚an improved circuit of the component was presented．In this circuit‚a symmetrical balanceable structure containing two components is adopted to perform the algebraic addition of output signals‚and the circuit nonlinearity is lessened by the selection of the partial voltage on either of the components‚thus obtaining optimal linearity．These proposed analytical equations are of great use to the nonl-i nearity analysis of the Gm-C filters constructed‚with the circuit units proposed above and their deduced method being applicable to other similar circuits．

Key words: integrated filter, Gm component, nonlinearity, analytic analysis