Parabolic antennas, and circular slot arrays, for the generation of Non-Diffracting Beams of Microwaves

TL;DR

This paper introduces novel antenna designs, including annular slits and parabolic reflectors, capable of generating non-diffracting microwave beams at around 10 GHz for applications like remote sensing.

Contribution

It presents two new antenna configurations for producing non-diffracting microwave beams, with detailed analysis and practical considerations for realistic apertures.

Findings

Annular slit arrays can generate non-diffracting microwave beams.

Parabolic reflectors with displaced spherical sources produce extended focus beams.

The proposed antennas are effective at 10 GHz with realistic aperture sizes.

Abstract

We propose in detail Antennas for generating Non-Diffracting Beams of Microwaves, for instance with frequencies of the order of 10 GHz, obtaining fair results even when having recourse to realistic apertures endowed with reasonable diameters. Our first proposal refers mainly to sets of suitable annular slits, having in mind various possible applications, including remote sensing. Our second proposal --which constitutes one of the main aims of this paper-- refers to the alternative, rather simple, use of a Parabolic Reflector, illuminated by a spherical wave source located on the paraboloid axis but slightly displaced with respect to the Focus of the Paraboloid. Such a parabolic reflector yields "extended focus" (non-diffracting) beams. [OCIS codes: 999.9999; 070.7545; 050.1120; 280.0280; 050.1755; 070.0070; 200.0200. Keywords: Non-Diffracting Waves; Microwaves; Remote sensing; Annular Arrays; Bessel beams; Extended focus; Reflecting paraboloids; Parabolic reflectors; Parabolic antennas].