  The temperature dependences of the enhanced critical current in wide and thin
Sn films exposed to the microwave field have been investigated experimentally
and analyzed. It was found that the microwave field stabilizes the current
state of a wide film with respect to the entry of Abrikosov vortices. The
stabilizing effect of irradiation increases with frequency. Using similarity
between the effects of microwave enhancement of superconductivity observed for
homogeneous (narrow films) and inhomogeneous (wide films) distributions of the
superconducting current over the film width, we have succeeded in partial
extension of the Eliashberg theory to the case of wide films.
