In this paper, a special photonic crystal fiber (PCF), which may be used in a WDM optical fiber transmission system for residual chromatic dispersion compensation, is designed and analyzed. The proposed structure is obtained by introducing a small Ge-doped core at the center of a conventional photonic crystal fiber. The behavior of the resulting geometry has been analyzed by an efficient vectorial finite element formulation with perfectly matched layer (PMLs). Numerical results show that the designed PCF presents flattened negative dispersion over E +S + C + L + U wavelength bands with an average dispersion near to - 203 ps.km-1.nm-1. ©2009IEEE.