The classical Kalman-Yakubovich-Popov Lemma provides a link between di
ssipativity of a system in state-space form and the solution to a line
ar matrix inequality. In this paper we derive the KYP Lemma for linear
systems described by higher-order differential equations. The result
is an LMI in terms of. the original coefficients in which the dissipat
ivity problem is posed. Subsequently we study the connection between d
issipativity and spectral factorization of polynomial matrices. This e
nables us to derive a new algorithm for polynomial spectral factorizat
ion in terms of an LMI in the coefficients of a polynomial matrix. (C)
1997 Elsevier Science B.V.