**On
the Yakubovich Frequency Theorem for linear
non-autonomous control processes**

with Roberta Fabbri and Russell Johnson,

*Discrete Cont. Dyn.
Sys. - Ser. A* **9** (**3**)
(2003), 677-704.

Using methods of the
theory of nonautonomous linear differential systems,
namely

exponential dichotomies and rotation numbers, some aspects of Yakubovich's

Frequency Theorem from periodic control systems are generalized to systems with

bounded uniformly continuous coefficients.