3D focal spot manipulation at millimeter waves

In this work a methodology to shape the near field of radiating apertures is presented. The technique, despite being generic, is applied to the specific scenario of shaping the focal pattern of a 12λ focusing aperture at 30 GHz. The main result comprises the capability to shrink/enlarge the focal depth, without affecting the spot diameter. To verify the concept, the acquired aperture distribution is mapped on a Radial Line Slot Antenna (RLSA), which has been manufactured and measured, showing excellent results.