Near-Field Focused Subarrays in a Multi-Panel Configuration

This paper investigates the focusing features of a multi-panel near-field focused (NFF) antenna. Differently from conventional NFF planar arrays, the proposed configuration is made of a set of NFF subarrays that are concentrically arranged over a cylindrical boundary. A systematic numerical analysis is performed to show how to control the shape of the -3dB focal spot through the main geometrical and electrical parameters of the proposed antenna layout, such as the number of subarrays, the focal spot location of each subarray and the radius of the cylindrical boundary the subarrays are arranged on. When compared with conventional planar NFF arrays, the additional mechanical complexity is partially balanced by a simpler feeding network design and a more symmetric focal spot. Experimental results are shown for a prototype operating at the 2.4 GHz ISM band.