Sub-reflectarrays for spherical aberration compensation: concept and simulations

The sub-reflectarray compensating technique is proposed for the spherical aberration compensation in this paper. A microstrip reflectarray is a low-profile, inexpensive, and easy-to-build antenna with phase controlling capability. It is utilized as a phase actuator in a spherical reflector. By properly adjusting the reflection phase of each reflectarray element, an equal phase distribution is achieved at the exit aperture plane of the spherical reflector, and the spherical aberration is thus corrected. A 35-m spherical reflector is selected as an example to validate this concept, and the simulation results show considerable improvement. Compared with the planar array feed compensating technique, this novel technique can provide a slightly better performance, and the potential losses in the beam forming network for array feed can be circumvented.