3D near-field shaping of a focused aperture

The near-field (NF) regime is a highly challenging and rather unstudied area of electromagnetic (EM) fields due to the high mathematical complexity that it presents. Nevertheless, the evanescent fields, present within the near field, can offer extra flexibility and freedom in molding the close-to-the-antenna field. In this work we develop an algorithm capable to shape the EM fields according to specifications in 3D regions at distances within the near-field and Fresnel region of the radiating device. The algorithm is based on a set theoretic approach and a frontand- back iterative propagation scheme, where the use of FFT is playing a key role in speeding up the algorithm's application. A prototype using a Radial Line Slot Antenna (RLSA) topology has been manufactured to prove the concept.

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