  Recently, a system with uniformly hyperbolic attractor of Smale-Williams type
has been suggested [Kuznetsov, Phys. Rev. Lett., 95, 144101, 2005]. This system
consists of two coupled non-autonomous van der Pol oscillators and admits
simple physical realization. In present paper we introduce amplitude equations
for this system and prove that the attractor of the system of amplitude
equations is also uniformly hyperbolic. Also we represent qualitative
illustrations as well as quantitative characteristics of a chaotic dynamics on
this attractor.
