Depolarization and position angle jumps due to relative longitude shift of pulsar beams

Pulsar radio emission is generally found to be linearly polarized over all longitudes of profiles, some times as high as up to 100%. The position angle sweep is in an ‘S’ shape, which can be well understood within the rotating vector model (Radhakrishnan & Cooke 1969). However, depolarization and position angle jumping are often found in the integrated profiles of some pulsars. In this paper, we investigate the effect on polarization behaviour due to relative phase shift between pulsar beam components caused by retardation effect, considering that the core and conal emission components are radiated from different heights. We conclude that the phase shift of beam centers of the different components could cause the depolarization and position angle jump(s) in integrated profiles.