<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A thin artificial magnetic conductor (AMC) structure is designed and breadboarded for radar cross-section (RCS) Reduction applications. The design presented in this paper shows the advantage of geometrical simplicity while simultaneously reducing overall thickness (for current <formula formulatype="inline"><tex>$\lambda/16$</tex></formula>). very pragmatic based on a combination AMC perfect...

This paper presents the design, fabrication, and characterization of a planar broadband chessboard structure to reduce radar cross-section (RCS) an object. The -like configuration is formed by combining two artificial magnetic conductor (AMC) cells. bandwidth limitations intrinsic AMC structures are overcome in this work properly selecting phase slope versus frequency both structures. A 180 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup>...

Low-loss high dielectric-constant materials are analyzed in the terahertz frequency range using time-domain spectroscopy. The dielectric constant and loss tangent for steatite, alumina, titania loaded polystyrene, zirconium-tin-titanate presented compared to measurements on high-resistivity silicon. For these materials, real part of ranges from 6 90. All samples were found have reasonable low-loss tangents. Applications as photonic crystal substrates antenna envisaged.

The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that shoot caused by a structurally well-characterized acid with sedimentary origin is functionally associated significant increases abscisic (ABA) root concentration hydraulic conductivity. Complementary experiments involving blocking agent of cell wall pores water transport (polyethylenglycol) conductivity...

This paper presents the design of a modulated metasurface (MTS) antenna capable to provide both right-hand (RH) and left-hand (LH) circularly polarized (CP) boresight radiation at Ku-band (13.5 GHz). is based on interaction two cylindrical-wavefront surface wave (SW) modes transverse electric (TE) magnetic (TM) types with rotationally symmetric, anisotropic-modulated MTS placed top grounded slab. A properly designed centered circular waveguide feed excites orthogonal (decoupled) SW...

This article presents the design of a flat Luneburg metalens antenna at V-band using gap waveguide (GW) technology. The consists parallel plate (PPW) loaded with metallic pins whose height is modulated to get an effective refractive index that follows equation. A Groove GW (GGW) H-plane horn used illuminate metalens, such rays are collimated and planar wavefront generated in direction propagation. Since structure hand planar, it can be efficiently integrated on surfaces. Moreover, fully...

The mutual coupling between dipole antenna array elements using a planar meta-surface as superstrate is experimentally investigated. based on grids of short metal strips and continuous wires. A comparison the when dipoles are radiating in free space presence presented. On average, 3 to 14 dB reduction achieved used. effect radiation performance studied by spherical near-field measurements pattern one driven fed others matched with 50 Omega loads. back-projected field aperture E-plane shown.

Resonant nanoparticles allow devices to be constructed selectively concentrate, guide, or scatter light in unique ways---for example, make highly efficient solar cells transparent displays. In this work, scientists develop a method intentionally design with desired characteristics. This approach provides promising new tool, which the authors demonstrate by designing novel nanoparticle laser.

The experimental validation of a Ku-band dual-circularly polarized (CP) broadside-beam metasurface (MTS) antenna is presented. A radially modulated anisotropic single-layer MTS has been synthesised employing subwavelength elliptical slotted metallic patches printed on top thin Arlon grounded substrate. In the structure, two decoupled phase-matched transverse magnetic and electric surface waves (SWs) are excited, which interact with leading to CP broadside radiation. Two different orthomode...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The design of a multifrequency dipole antenna array based on resonant meta-surface superstrate is proposed. behavior single element that closely placed to experimentally investigated. proposed resonating unit cells formed by capacitively loaded strips and split ring resonators. By tuning the pass band meta-surface, physical area effectively illuminated enhancing radiation performance. gain,...

This contribution presents an analytical formulation for the electromagnetic response of grids ferromagnetic microwires, where fields produced by structure are found means local field method. In addition, a circuit analogy is introduced better understanding grid response, single microwire modeled as impedance-loaded wire, and transmission-line approach used whole grid. Moreover, homogenization considered to provide more physical insight into internal polarizations Contrary previous...

We demonstrate that superbackscattering responses can be excited in subwavelength dielectric particles with simple geometries. The response arises from the simultaneous, coherent excitation of electric dipole and magnetic quadrupole resonances. Its signature is a superdirective scattering pattern simultaneously pointing towards both forward backward directions. practical implementation this effect Tellurium operating thermal infrared also addressed. examples presented reveal spherical...

Initial measurements are presented of a dipole antenna mounted on top photonic crystal structure at terahertz frequencies. The configuration and test setup described. the has higher directivity in contrast to single element. ability this technology suppress surface waves is noted.

Two different electromagnetic bandgap (EBG) superstrate array antenna configurations, intended for the wide area augmentation service space segment, are presented in this paper. The described configurations take advantage of directivity enhancement produced by a semireflective sheet placed parallel to metallic ground plane. first design is realized using 2times2 circularly polarized (CP) patch illuminating an EBG composed square pattern circular holes etched thin sheet. second consists CP...

This paper presents the design, manufacturing, and characterization of a waveguide based on electromagnetic-bandgap (EBG) technology working in W-band. A modified silicon EBG woodpile structure was used order to improve matching performance standard rectangular waveguide. The transition between conventional WR10 optimized 13.5% bandwidth around 90 GHz achieved. measured insertion losses remained better than 3 dB overall bandwidth.

A simplified design of an inline transition between microstrip and rectangular waveguide is presented in this paper. The makes use a dielectric filled (DFRW) as intermediate step, which simplifies manufacturing allows for analytical design. behavior the has been experimentally validated W-band by means back-to-back configuration. Good performance achieved: return loss greaterthan 10 dB mean insertion lower than 1 dB.

We investigate the role of quantum interference phenomena on characteristics fields radiated by an array emitters. In analogy to, but distinct from, classical outcomes, we demonstrate that geometry empowers control over direction-dependent photon statistics arbitrary order. Our formulation enables recognition configurations providing spatial correlations with no counterpart. For example, identify a system in which angular distribution average number photons is independent and position...

Reactive power plays a crucial role in the design of small antenna systems, but its impact on bandwidth quantum emitters is typically disregarded. Here, we theoretically demonstrate that there an intermediate domain between usual weak and strong coupling regimes where emitter directly related to dispersion properties reactive power. This result emphasizes must be understood as additional degree freedom engineering emitters. We illustrate applicability this concept by revisiting typical...

This paper presents a theoretical modeling of the scattering ferromagnetic microwires in free space and inside rectangular waveguide, providing both an analytical solution physical interpretation problem. Special attention is devoted to impact microwire radius its magnetic properties. Theoretical results have been experimentally verified measuring reflection, absorption, transmission coefficients waveguide.

The physical limitations on time-harmonic scattering processes are investigated the basis of optical theorem. Previously derived least upper bounds total and absorption cross sections obtained from it in a straightforward manner. In addition, reveals practical bound for bistatic cross-section when evaluated any direction. It is proved further that maximum section occurs forward-scattering direction corresponding backscattering four times smaller than this value. Metamaterial-inspired...

Near-field electromagnetic trapping of particles is generally obtained by means gradient forces. In this paper, we discuss the attractive behavior curl-spin forces, as well their potential for near-field and manipulation. It demonstrated that forces enable operating at resonant frequency. Such phenomena can be exploited to design more efficient selective traps, boost energy exchange systems, bring stability coupled radiators. also illustrated how balance between gradient, radiation pressure,...

This paper presents the design, fabrication and measurements of a fourth-harmonic Schottky diode mixer working at sub-millimeter frequencies, in particular an RF frequency 440 GHz. Measured DSB noise temperature 7900 K conversion loss 14 dB have been obtained. configuration offers alternative solution which simplifies LO signal generation. It can find application imaging systems, where arrays detectors need to be simultaneously fed by same LO.

The force density induced by electromagnetic fields in electrically and magnetically polarizable media is studied analytically. Different formulations of the as a function field-related quantities, including spatial derivatives fields, gradients field intensity, phase gradients, power flow (Poynting vector field), kinetic momentum flow, are introduced. These retain certain symmetries with respect to expressions introduced previous works for an isolated particle but also point out fundamental...