I'll assume you don't know much about solar sails, this may not be the case.

The force from the light of a star on a solar sail and the force of gravity which points in the opposite direction both follow the inverse square law.

A solar sail that can station keep can do it anywhere, with respect to the sun.
For example, you could use a solar sail to sit on the suns polar axis in no orbit at all.

Now, in case of an Earth orbit, you manuver the aspect of the sail dynamically so as to balance a component of Earths gravity on the sail. This way, an artificial central force potential is created to 'orbit' within.

That way the sail+sat bus end up orbiting in a plane, parallel (or nearly so) to the Earths equatorial plane, but above the poles.