  The goal of this article is to show that the following two categories are
equivalent (1) the category of filtered (phi,N,G_K)-modules (2) the category of
(phi,Gamma_K)-modules over the Robba ring such that the Lie algebra of Gamma_K
acts locally trivially.
  Furthermore, we show that under this equivalence, the admissible filtered
(phi,N,G_K)-modules correspond to the etale (phi,Gamma_K)-modules, which gives
a new proof of Colmez-Fontaine's theorem.
