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In this paper, we proposed a half-wave plate, which works at millimeter-wave band, based on a field transformation(FT) method with wide incident angle and broad working bandwidth. The proposed waveplate is composed of periodically arranged two dielectric layers with sub-wavelength heights. The effective electromagnetic(EM) parameters of the proposed waveplate can be tuned by manipulating the heights...
The recently developed concept of two dimensional metamaterial — the metasurface, provides more convenient method to manipulate electromagnetic wave in a designable way within subwavelength distance. However, most of the metasurface designs rely on the meta-atom's properties to achieve certain EM wave control. In this presentation, we propose the top-down design method of metasurface through the surface...
Selective wave-transmitting absorbers (STAs), which have one or more narrow transmission bands among a wide absorption band are often demanded in wireless communication and stealth technology. They can be used in many applications such as reducing antennas' radar cross section, reducing the coupling between different systems and improving anti-jamming capability. However it is difficult to realize...
Most of the metasurfaces are composed with subwavelength building blocks of passive metallic and dielectric resonators; therefore, once the structures are designed and fabricated, their electromagnetic (EM) properties and spectral responses cannot be changed. However, dynamic control of EM wave propagation is often demanded in many practical applications, such as the dynamic beam-forming and scanning...
In this paper, a novel broadband microwave metamaterial absorber is successfully realized by randomly distributed metallic loop-shaped elements. Such amorphous arrangement of single-sized elements can result in a spatially disordered distribution of multi-resonance absorption, thus dramatically improving the absorption bandwidth. On this basis, we further broaden the bandwidth by using three differently...
A flexible low-scattering metasurface is presented in the paper. By randomly distributing various dimensional elements along the surface, the proposed design can mimic a diffuse reflection surface, achieving a broadband backward low-scattering property. Through optimization, flexible samples composed of metallic-element-printed film and flexible substrate are designed, fabricated and measured in microwave...
A broadband metamaterial (MM) absorber based on water droplets is proposed and investigated in this paper. The proposed MM absorber is composed of a periodic array of holes drilled in the dielectric substrate which are then filled with water droplets. The absorption property of such water absorber can be tuned by manipulating the volume of the water droplets. Through optimized design, a broadband...
This paper presents a novel design of orientation distributed digital metasurface for suppressing backward radar cross section (RCS) with a broad working bandwidth. A corrugated meander line is proposed as the constitutive unit cell which is capable of creating 1-bit (with two orientations of 0° and 90°), 2-bit (with four orientations of 0°, 45°, 90° and 135°) and multi-bit elements by different orientations...
Dynamic control of electromagnetic (EM) wave propagation (both the amplitude and phase) is essential to many practical applications. The recently developed two dimensional metamaterial — the metasurface, provides more convenient method to manipulate EM wave in a designable way within subwavelength distance. Here we incorporate electrical tunable elements into the metasurface designs to realize dynamic...
In this paper, we focused on the study of electromagnetic (EM) wave propagation in a particular anisotropic medium—Infinity-anisotropic (IA) metamaterial. IA metamaterials, which include infinity index-anisotropic and infinity loss-anisotropic metamaterial, have the ability to suppress the diffraction limit of EM wave. Thus the deep subwavelength wave could propagate in the IA metamaterials without...
Recently, orbital angular momentum (OAM) electromagnetic wave is of great interest owing to their unique properties and potential applications in areas such as communication, and radar technology. Particularly it may provide a new solution of the crisis of frequency domain allocation. However there are lots of unsolved problems, especially in the design of practical system. For example, the transmitter...
We present here a wide-angle broadband waveplate based on a field transformation (FT) method. By adjusting the thickness of such a waveplate, we obtain both half-wave and quarter-wave plates which achieve polarization conversions between TE and TM, LCP and RCP, linear and circular polarizations separately for both transmission and reflection cases. Such waveplates can be realized through sub-wavelength...
Quasi-conformal transformation optics (QCTO) provides a practical approach to design nonmagnetic broadband medium for electromagnetic devices, here we present a novel hybrid method of QCTO with array synthesis, and apply it to conformal phased array antenna (PAA) design which makes the complex conformal PAA can behave like a geometrically different array with wide scanning range when surrounded with...
This paper presents a broadband wide-angle polarizer based on a field transformation (FT) method. By adjusting the thickness of such a polarizer, we achieve polarization conversions between TE and TM, LCP and RCP, linear and circular polarizations respectively for both transmission and reflection cases. Such a polarizer can be realized through sub-wavelength dielectric gratings based on the effect...
In this paper, we report a metamaterial absorber with nearly octave bandwidth in the microwave frequency. We employ resistance loaded resonance unit cells to reduce the quality factor of the resonance in the metamaterial and expand the absorption bandwidth. The proposed planar metamaterial absorber composes two slabs of print circuit board (PCB) bonded together. The upper one is a dielectric with...
This paper presents a reflective broadband wide-angle polarizer based on a field transformation (FT) method. By adjusting the thickness of such a polarizer, we achieve polarization conversions between TE and TM, LCP and RCP, linear and circular polarizations respectively. Such a polarizer can be realized through sub-wavelength dielectric gratings based on the effective medium theory, their performance...
This paper reports a polarization selective one-way microwave absorber based on composite metamaterial slabs. The polarization selective one-way absorber allows a linearly polarized electromagnetic wave to be absorbed along one particular incident direction and to penetrate through it along the opposite direction. For the cross-polarized wave, the direction dependent propagation properties are reversed...
The control of electromagnetic wave propagation is an important issue in either fundamental electromagnetic research or device application technologies. In this presentation we incorporate the active element into the metasurface concept to achieve dynamic control of electromagnetic wave reflection. We will present the application of active metasurfaces to the control of the polarization and phase...
Swiss rolls, consisting of a helically wound metal/dielectric laminate tape are utilized to achieve a novel ultrathin metamaterial absorber (MA) with a thickness of only about less than two percent of the incident wavelength. An intense magnetic resonance happens accompanied by strong absorption efficiency above 95% for both the TE and TM incident waves at the resonant frequency with the incidence...
In this paper, the dispersions and electromagnetic wave transmission of higher-order modes in a kind of ultra-thin spoof surface plasmonic structures, the conformal surface plasmon (CSP) structure, have been explored at microwave frequency. The transmission spectrum shows a multi-passband characteristic. To eliminate the radiation loss associated with the higher-order modes, a ground plane is introduced...
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