Analysis and Design of Bessel Beam Launchers: Transverse Polarization

In this communication, we present a theoretical analysis, 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 ${z}$ -propagation 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 the 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 circular-polarized 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 then been fabricated at $f = 30$ GHz. The measured transverse electric field component shows a satisfactory agreement with full-wave numerical simulations.