Analysis and Design of Bessel Beam Launchers: Transverse Polarization

Abstract

In this paper, we present a theoretical analysis, one design and fabrication of a limited-diffractive planar Bessel beam launcher, that exhibits a zeroth order Bessel profile in the transverse electric field component with respect to the zpropagation axis. The launcher is designed by synthesizing a finite zeroth order, first kind Hankel aperture distribution, polarized along a fixed polarization unit vector. The field radiated by such an aperture distribution is derived by following an approximate model based on geometric theory of diffraction, thus allowing to highlight the relevant wave constituents involved in transverse Bessel beam generation, also including the effect of aperture truncation on the radiated beam. Moreover, the theoretical analysis has been profitably applied to the design of a circularpolarized planar transverse Bessel beam launcher by means of a slotted radial waveguide. A prototype of right-handed circular polarized (RHCP) transverse Bessel beam launcher has been then fabricated at f = 30 GHz. The measured transverse electric field component shows a satisfactory agreement with full-wave numerical simulations.

Effects of a Cylindrical Metallic Cavity on the Radiation of Longitudinally Polarized Limited-Diffractive Bessel Beams

“…To validate the theoretical approach discussed in Section II versus a full-wave simulator (COMSOL multiphysics), three examples of cavities are proposed in the following, all fed by the magnetic current distribution (1), with an axicon angle [2] of θ a = 15 • , and free-space wavenumber normalized to the wavelength (k = 2π rad/m). Indeed, as it has been demonstrated in [4] and [6], ( 1) is able to radiate a longitudinally polarized limited-diffractive Bessel beam in free space. Instead, when it radiates inside a PEC cavity, cavity mode discretization unavoidably occurs, as shown theoretically in (13) and (14) and in (15) and (16).…”

“…Interestingly, in the last decade, high-efficiency Bessel beams have been successfully designed at microwaves and millimeter waves [2], [22], by exploiting different but complementary approaches, such as holography on radial-line slot arrays [4], [6], [9], metasurfaces [23], or leaky-wave-based approaches [3]. Moreover, mature planar technologies, such as printed circuit board (PCB), are available for compact Bessel-beam launcher fabrication so that real applications of Bessel beams at microwaves and millimeter waves do not represent only an idealization, but instead a promising reality.…”

A compact linearly polarized RLSA antenna integrated with circular ring resonator (CRR) for 5G mm-wave applications

“…The capacitance (C) value of the radiating slots can be obtained from the slot area over the thickness of the slot as noted in [25]:…”

“…The equivalent dielectric constant (ε req ) can be determined from the thickness of dielectric (t) for determining the length of radiating slots, written in equation (18) [25]:…”

Forward and Inverse Scattering of Metallic Objects Through Focused Bessel-Shaped Fields

“…(1) 0 (•). In (1), k ua = k sin θ a is the imposed wavenumber on the primary current distribution, k = ω 0 /c the free-space wavenumber, and θ a the axicon angle describing the BF [15], [21], while Π u L denotes the rectangular function of width L centered at u = 0. Such an inward cylindrical traveling wave distribution is able to radiate a focused BF in the xy plane.…”