Optimal H/sub /spl infin// deconvolution filters robust fault detection of uncertain polytopic linear systems subject to unknown input disturbance are described. The filter must be capable to satisfy two sets of H/sub /spl infin// constraints: the first is a disturbance attenuation and decoupling requirement whereas the second expresses the capability of the filter to enhance the fault signals. By means of the projection lemma and congruence transformations, a quasiconvex formulation of the problem is obtained via LMIs. The effectiveness of the design technique is illustrated via a numerical example.