Metasurfaces constitute a class of thin metamaterials, which are used from microwave to optical frequencies create new antennas and devices. Here, we propose the use variable-impedance metasurfaces for transforming surface or guided waves into different wavefield configurations with desirable properties. We will shortly refer this metasurface-driven transformation as “metasurfing.” Metasurfing can be obtained by an appropriate synthesis inhomogeneous metasurface reactance that allows local...

Different kinds of spiral planar circularly polarized (CP) antennas are presented. These based on an interaction between a cylindrical surface-wave excited by omnidirectional probe and inhomogeneous surface impedance with pattern. The transforms bounded wave into leaky almost broadside radiation. problem is studied adiabatically matching the local 2D solution modulated surface-impedance to actual surface. Analytical expressions derived for far-field radiation pattern; this basis, universal...

A metasurfing concept is demonstrated and applied in the design of Luneburg lens antennas. Using an array size-varying circular patches on a dielectric substrate inside parallel-plate waveguide (PPW) structure variable surface impedance obtained, which realizes equivalent refraction index as that lens. The obtained has good bandwidth characteristics significant fabrication advantages with respect to conventional lenses. Based this PPW lens, H-plane antenna been designed simulated.

A method is presented, for the efficient derivation of dispersion equation associated with electromagnetic bandgap (EBG) structures composed by lossless frequency selective surfaces (FSS) printed on stratified dielectric media. The method, valid range where a single propagating Floquet mode occurs, based Foster's reactance theorem applied to an equivalent transmission line network. This implies that admittance functions which represent FSS satisfy pole-zero analytical properties driving...

This paper presents a flat, high gain, wide scanning, broadband continuous transverse stub (CTS) array. The design procedure, the fabrication, and an exhaustive antenna characterization are described in details. array comprises 16 radiating slots is fed by corporate-feed network hollow parallel plate waveguide (PPW) technology. A pillbox-based linear source illuminates corporate allows for beam steering. designed using ad hoc mode matching code recently developed CTS arrays, providing...

We describe the design of a radial line slot array antenna with shaped and focused near field. The is designed in such way to control side lobe level beamwidth normal component electric field respect radiating aperture. procedure consists two steps. In first step, requirements on near-field pattern are provided over focusing plane at given distance from A set theoretic approach then used derive aperture distribution fitting second synthesized by accurately placing sizing slots antenna....

A dual-layer pillbox antenna is proposed for mechanical beam-scanning applications at millimeter-wave frequencies. It consists of three main subsystems (multislot quasi-optical transition, input part, and radiating part). The parts are placed in two different layers, the transition behaves as a 180 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{\circ} ~E$</tex></formula> -plane coupler-type bent....

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In this paper, we prove experimentally that nondiffractive Bessel beams can be generated by using inward cylindrical traveling wave aperture distributions. An azimuthally invariant distribution is defined over the of a radial line slot array (RLSA) to launch beam whose normal electric-field component assumes truncated, zeroth-order function. optimization procedure based on holographic approach used for tuning position and size slots RLSA. The antenna centrally fed coaxial probe transition....

In this communication, it is shown that a nondiffracting vortex beam (i.e., higher order Bessel with azimuthal phase variation) can be generated in the near field by synthesizing an inward cylindrical traveling-wave distribution over finite aperture antenna. A radial line slot array (RLSA) then designed to prove concept. The collimated excited proximity of RLSA, within region properly defined range beam. dependence longitudinal electric vortex-beam magnitude follows first-order function, and...

This paper deals with the design of scalar metasurface antennas capable radiating a well-polarized beam in far-field or near-field zones. The equivalent electric current over is used to derive equations generate desired field pattern based on impedance condition. In particular, it shown that metasurfaces can be linear and circular polarizations for fixed pointing direction far by properly changing locally boundary addition, they also normal polarized Bessel beams region. Several solutions...

This paper introduces a rigorous and effective modeling framework for the continuous transverse stub (CTS) array, based on spectral Green's function approach. A multimodal expansion of equivalent currents over slots is used to derive an accurate expression active impedance infinite array. formula validated through comparisons with full-wave simulations when array scans are in principal planes. The mathematical formulation highlights broadband properties CTS arrays accurately predicts impact...

In this paper the focusing capability of a radiating aperture implementing an inward cylindrical traveling wave tangential electric field distribution directed along fixed polarization unit vector is investigated. particular, it shown that such generates non-diffractive Bessel beam whose transverse component (with respect to normal aperture) takes form zero-th order function. As practical implementation theoretical analysis, circular-polarized launcher, made by radial parallel plate...

This paper deals with the design of tensorial modulated metasurfaces able to implement a general radiating aperture field distribution. A new synthesis approach is introduced, based on local holography and variable impedance modulation. In particular, it shown that can be used generate distribution (phase amplitude). addition, step by algorithm presented. order validate method, several solutions are presented at 20 GHz which distributions radiate different beams polarization.

In this communication, we present a theoretical analysis, design, and fabrication of limited-diffractive planar Bessel beam launcher, that exhibits zeroth-order profile in the transverse electric field component with respect to z-propagation axis. The launcher is designed by synthesizing finite zeroth-order, first kind Hankel aperture distribution, polarized along fixed polarization unit vector. radiated such an distribution derived following approximate model based on geometric theory...

A mode-matching method is proposed for the accurate and fast analysis of structures composed by metallic dielectric posts in a parallel-plate waveguide environment. The incident scattered fields on each post are expressed with cylindrical mode expansion. After enforcing appropriate boundary conditions, set matrix equations derived. corresponding solution coefficients field vector validated several examples found literature compared results obtained commercial software Ansys HFSS. can be used...

We propose a fast and accurate full-wave code capable of analyzing electrically large substrate integrated waveguides consisting stacked parallel-plate hosting dielectric or metallic posts coupling and/or radiating slots. Boundary conditions enforced on yield scattering amplitudes, while slots are modeled by equivalent magnetic currents, solved method moments. Substantial accelerations proposed to exploit various symmetries the structures select optimal number modes according relevant...

The manipulation of the near-field (NF) is a challenging topic in electromagnetics, carrying essential importance for several applications. In this paper, we develop an algorithm capable shaping NF 3-D domains according to given specifications. based on set theoretic approach and front-and-back iterative propagation scheme. latter realized using fast Fourier transforms (FFT), reducing required computational time. applied focal scenario. case, full control depth focus, spot diameter, sidelobe...

We introduce here a new dual-layer multibeam antenna with folded Rotman lens used as compact beam forming network in SIW technology. The objective is to reduce the overall size of system by folding on two layers along array port contour and using transition based an exotic reflector several coupling vias holes. To validate proposed concepts, has been designed at 24.15 GHz. radiating structure slotted waveguide made fifteen resonant waveguides. simulated results show very good scanning...

This article presents a circularly polarized corporate-fed radial-line slot antenna (CF-RLSA) operating in Ka-band and realized low-cost, low-profile printed circuit board (PCB) technology. The radiating aperture is fed by corporate feed network based on broadband pillbox-like circular transition. proposed feeding system results 67% gain bandwidth improvement compared to classical center-fed radial line (RLSA) designs. Pattern stability versus frequency also achieved. provided the...

In this paper, the authors present a method for analysis of lossy Substrate Integrated Waveguide (SIW) structures.The is achieved through cylindrical-wave mode expansion field and matching technique to enforce boundary conditions on post surfaces.We introduce an approximated formulation previous exact procedure, valid in microwave regime, numerically examine number devices using both analyses.These include filters, couplers, phase shifter, etc. Results are presented scattering parameters...

A Luneburg lens designed by using a variable artificial surface is reported. Planar inside parallel waveguide Fakir's bed of nails substrate to modulate the impedance on boundary in order obtain desired refraction index for guided wave.

In this paper, we present a technique for the automatic optimization of right-hand circular-polarized (RHCP) linear slotted array in substrate integrated waveguide (SIW) technology so-called "last-mile"communications, which narrow (broad) beam is required elevation (azimuthal) plane. The procedure can be divided into two steps; i) isolated single slot pairs, by means physics-based functionals able to minimize both pair back-scattering and axial-ratio, ii) entire global functional match...