The offset dish antenna still uses a parabolic dish with the driven element at the focus of the parabola; however, the curve of the dish is taken from one side of the parabola instead of the center.
Offset fed antennas are most commonly found on Ku Band DBS satellite dishes or ‘mini-dishes’. The benefit of the offset configuration is that it positions the feed horn away from the dish itself so that it does not cast a shadow on the dish. Offset dishes are often referred to as ‘asymmetrical’.