A general class of current mode filters

A new class of nonlinear analog filters with linear input-output response is proposed. These filters are an extension of the recently introduced 'log filter' class. By virtue of the small node voltage excursions, these filters share the current mode characteristic of log filters. It is shown that the equations for the filter are obtained by using hyperbolic functions for mappings on the state space in linear systems. The resulting exponential state space filters are then given circuit implementations.<<ETX>>