  A change in the effective permittivity of a ferroelectric film in the
paraelectric phase under the action of a strong high-frequency field
(nonequilibrium soft mode heating) is considered. It is shown that this effect
must be most clearly pronounced far from the resonance (\omega_0 << \omega_sm),
rather than for the external field frequency \omega_0 close to the soft mode
frequency \omega_sm. The effective permittivity as a function of the
high-frequency field amplitude is calculated using the phenomenological
approach and within the microscopic theory based on the simple model of a
displacement-type ferroelectric.
