  The beamed radio emission from relativistic plasma (particles or bunches),
constrained to move along the curved trajectories, occurs in the direction of
velocity. We have generalized the coherent curvature radiation model to include
the detailed geometry of the emission region in pulsar magnetosphere, and
deduced the polarization state in terms of Stokes parameters. By considering
both the uniform and modulated emissions, we have simulated a few typical pulse
profiles. The antisymmetric type of circular polarization survives only when
there is modulation or discrete distribution in the emitting sources. Our model
predicts a correlation between the polarization angle swing and sign reversal
of circular polarization as a geometric property of the emission process.
