Near-field focused antennas: from optics to microwaves

In this paper, a review on near-field focused (NFF) antennas for short-range wireless links at the microwave frequency band is presented. The basic working principles, the design guidelines, as well as the synthesis procedures suggested for the near-field shaping around the focal point, will be addressed. The review will also span on the different technologies used to implement NFF antennas at the microwave frequency band.