An offset-fed flat reflectarray antenna with improved bandwidth property

Plane reflector is a two dimensional array which consists of apertures or patchesthis kind of reflectarray is always illuminated by a primary feed hornand then compensate the spatial phase delay by the elements printed on the surface. The main advantage of this structure is the main beam can be designed to tilt or scan a number of beamwidths away from its broadside direction. But the most significant defect is it's narrow bandwidth, which is caused by the elements and reflector's operating principle. In this paper, we introduced a new kind of broadband element consist of hexagon loops and patch, which has more than 500 degree linear phase. And we give an offset-fed reflectarray antenna comprised of this elements which acquire 23.6% 1 dB bandwidth, this has a significant improvement for traditional structures.