Measurement campaign of the Ka-band discrete lens antenna for multibeam applications

A spherical discrete lens antenna based on the back-to-back combination of two arrays of choked horn antennas interconnected with smooth waveguides sections implementing the spherical phasing law, has been designed, simulated, fabricated and measured. The spherical phasing law of the lens converts the incoming spherical phase front, from a small feeder placed at the focal plane, in a plane phase front; and depending on the position of the feeder at the focal plane (the perpendicular plane to the lens axis containing the focal point), the beam could be pointed at different directions. The minimum angular distance between two beams is directly related to the minimum distance between two adjacent positions of low directivity and, therefore, small feeders. In this paper, the results of the measurement campaign will be presented, proving the tri-dimensional pointing capability of the lens as the feeder moves on the focal plane.