Showing papers on "Metamaterial absorber published in 2013"
TL;DR: In this article, a zero-index metamaterial formed by stacked silicon rod unit cells is proposed to realize all-dielectric impedance-matched zero index metammaterials operating at optical frequencies.
Abstract: Previously demonstrated zero- or negative-refractive-index metamaterials at optical frequencies suffer from large ohmic losses because of the need to use metals. Metamaterials formed by stacked silicon rod unit cells allow the realization of all-dielectric impedance-matched zero-index metamaterials operating at optical frequencies, potentially benefiting the development of angular-selective optical devices.
585 citations
TL;DR: A graphene based perfect absorber is demonstrated and the properties of graphene wire medium and graphene fishnet metamaterials are investigated and both narrowband and broadband tunable absorbers are demonstrated.
Abstract: In this paper we present the efficient design of functional thin-film metamaterial devices with the effective surface conductivity approach. As an example, we demonstrate a graphene based perfect absorber. After formulating the requirements to the perfect absorber in terms of surface conductivity we investigate the properties of graphene wire medium and graphene fishnet metamaterials and demonstrate both narrowband and broadband tunable absorbers.
526 citations
TL;DR: The results show that fundamental light interactions of surfaces can be dynamically controlled by all-electronic means and provide a path forward for realization of novel applications.
Abstract: We present an experimental demonstration of electronically tunable metamaterial absorbers in the terahertz regime. By incorporation of active liquid crystal into strategic locations within the metamaterial unit cell, we are able to modify the absorption by 30% at 2.62 THz, as well as tune the resonant absorption over 4% in bandwidth. Numerical full-wave simulations match well to experiments and clarify the underlying mechanism, i.e., a simultaneous tuning of both the electric and magnetic response that allows for the preservation of the resonant absorption. These results show that fundamental light interactions of surfaces can be dynamically controlled by all-electronic means and provide a path forward for realization of novel applications.
480 citations
TL;DR: A new type of metamaterial operating in the optical part of the spectrum that is three orders of magnitude faster than previously reported electrically reconfigurable meetamaterials is developed.
Abstract: Current efforts in metamaterials research focus on dynamic functionalities such as tunability, switching and modulation of electromagnetic waves. To this end, various approaches have appeared, including embedded varactors, phase-change media, use of liquid crystals, electrical modulation with graphene and superconductors, and carrier injection or depletion in semiconductor substrates. However, tuning, switching and modulating metamaterial properties in the visible and near-infrared range remain major technological challenges: the existing microelectromechanical solutions for the subTHz and THz regimes cannot be shrunk by 2-3 orders of magnitude to enter the optical spectral range. Here we develop a new type of metamaterial operating in the optical part of the spectrum which is 3 orders of magnitude faster than previously reported electrically reconfigurable metamaterials. The metamaterial is actuated by electrostatic forces arising from the application of only a few volts to its nanoscale building blocks, the plasmonic metamolecules, which are supported by pairs of parallel strings cut from a nanoscale thickness flexible silicon nitride membrane. These strings of picogram mass can be synchronously driven to megahertz frequencies to electromechanically reconfigure the metamolecules and dramatically change the metamaterial’s transmission and reflection spectra. The metamaterial’s colossal electro-optical response allows for both fast continuous tuning of its optical properties (up to 8% optical signal modulation at up to megahertz rates) and high-contrast irreversible switching in a device of only 100 nm thickness without the need for external polarizers and analyzers.
346 citations
TL;DR: In this article, a polarization-insensitive tunable tunable metamaterial absorber with varactor diodes embedded between metammaterial units is presented. But the design, analysis and measurements of the tunability of the absorber are not discussed.
Abstract: We present the design, analysis and measurements of a polarization-insensitive tunable metamaterial absorber with varactor diodes embedded between metamaterial units. The basic unit shows excellent absorptivity in the designed frequency band over a wide range of incident angles. By regulating the reverse bias voltage on the varactor diode, the absorption frequency of the designed unit can be controlled continuously. The absorption mechanism is interpreted using the electromagnetic-wave interference theory. When the metamaterial units are placed along two orthogonal directions, the absorber is insensitive to the polarization of incident waves. The tunability of the absorber has been verified by experimental results with the measured bandwidth of 1.5?GHz (or relative bandwidth of 30%).
290 citations
TL;DR: The near-perfect absorptions of dual, triple and quad peaks are persistent with polarization independence, and the effect of angle of incidence for both TE and TM modes was also elucidated.
Abstract: We propose multi-band metamaterial absorbers at microwave frequencies. The design, the analysis, the fabrication, and the measurement of the absorbers working in multiple bands are presented. The numerical simulations and the experiments in the microwave anechoic chamber were performed. The metamaterial absorbers consist of an delicate arrangement of donut-shape resonators with different sizes and a metallic background plane, separated by a dielectric. The near-perfect absorptions of dual, triple and quad peaks are persistent with polarization independence, and the effect of angle of incidence for both TE and TM modes was also elucidated. It was also found that the multiple-reflection theory was not suitable for explaining the absorption mechanism of our investigated structures. The results of this study are promising for the practical applications.
279 citations
TL;DR: The radiative properties of metamaterial nanostructures made of two-dimensional tungsten gratings on a thin dielectric spacer and an opaque tungsen film from UV to mid-infrared region as potential selective solar absorbers will facilitate the design of novel highly efficient solar absorber to enhance the performance of various solar energy conversion systems.
Abstract: In this work, we numerically investigate the radiative properties of metamaterial nanostructures made of two-dimensional tungsten gratings on a thin dielectric spacer and an opaque tungsten film from UV to mid-infrared region as potential selective solar absorbers. The metamaterial absorber with single-sized tungsten patches exhibits high absorptance in the visible and near-infrared region due to several mechanisms such as surface plasmon polaritons, magnetic polaritons, and intrinsic bandgap absorption of tungsten. Geometric effects on the resonance wavelengths and the absorptance spectra are studied, and the physical mechanisms are elucidated in detail. The absorptance could be further enhanced in a broader spectral range with double-sized metamaterial absorbers. The total solar absorptance of the optimized metamaterial absorbers at normal incidence could be more than 88%, while the total emittance is less than 3% at 100°C, resulting in total photon-to-heat conversion efficiency of 86% without any optical concentration. Moreover, the metamaterial solar absorbers exhibit quasi-diffuse behaviors as well as polarization independence. The results here will facilitate the design of novel highly efficient solar absorbers to enhance the performance of various solar energy conversion systems.
273 citations
TL;DR: This work introduces a class of artificial media: high temperature Epsilon-near-Pole metamaterials consisting of plasmonic materials with high melting point and shows that they can be used as efficient narrowband omnidirectional thermal emitters in thermophotovoltaic systems.
Abstract: We propose a method for engineering thermally excited far field electromagnetic radiation using epsilon-near-zero metamaterials and introduce a new class of artificial media: epsilon-near-pole metamaterials. We also introduce the concept of high temperature plasmonics as conventional metamaterial building blocks have relatively poor thermal stability. Using our approach, the angular nature, spectral position, and width of the thermal emission and optical absorption can be finely tuned for a variety of applications. In particular, we show that these metamaterial emitters near 1500 K can be used as part of thermophotovoltaic devices to surpass the full concentration Shockley-Queisser limit of 41%. Our work paves the way for high temperature thermal engineering applications of metamaterials.
244 citations
14 Mar 2013
TL;DR: This paper will report some recent progress on wireless power transfer (WPT) based on resonant coupling, and the use of metamaterials and array of coupled resonators.
Abstract: In this paper, we will report some recent progress on wireless power transfer (WPT) based on resonant coupling. Two major technologies will be discussed: the use of metamaterials and array of coupled resonators. With a slab of metamaterial, the near-field coupling between two resonant coils can be enhanced; the power transfer efficiency between coils is boosted by the metamaterial. The principle of enhanced coupling with metamaterial will be discussed; the design of metamaterial slabs for near-field wireless power transfer will be shown; recent experimental results on wireless power transfer efficiency improvement with metamaterial will also be presented. By using an array of resonators, the range of efficient power transfer can be greatly extended. More importantly, this new technology can provide wireless power to both static and mobile devices dynamically. The principle of this technology will be explained; analytical and numerical models will be used to evaluate the performance of a WPT system with an array of resonators; recent experimental developments will also be presented.
230 citations
TL;DR: In this article, a perfect metamaterial absorbing structure over a thin low-loss grounded substrate is studied by resorting to an efficient transmission line model, which allows the derivation of simple and reliable closed formulas describing the absorption mechanism of the subwavelength structure.
Abstract: A popular absorbing structure, often referred to as Perfect Metamaterial Absorber, comprising metallic periodic pattern over a thin low-loss grounded substrate is studied by resorting to an efficient transmission line model. This approach allows the derivation of simple and reliable closed formulas describing the absorption mechanism of the subwavelength structure. The analytic form of the real part of the input impedance is explicitly derived in order to explain why moderate losses of the substrate is sufficient to achieve matching with free space, that is, perfect absorption. The effect of the constituent parameters for tuning the working frequency and tailoring the absorption bandwidth is addressed. It is also shown that the choice of highly capacitive coupled elements allows obtaining the largest possible bandwidth whereas a highly frequency selective design is achieved with low capacitive elements like a cross array. Finally, the angular stability of the absorbing structure is investigated.
228 citations
TL;DR: In this article, an ultrathin and broadband absorber is investigated, which is composed of a periodic array of loop-dielectric multilayered structure, and the authors show that the absorption at normal incidence is above 90% in the frequency range of 8.37-21 GHz.
Abstract: An ultrathin and broadband absorber is investigated in this paper. The metamaterial absorber is composed of a periodic array of loop-dielectric multilayered structure. By tuning the scale factor of the loop and the height of every layer, a desirable refractive index dispersion spectrum is realized, which is the reason to realize a successive anti-reflection in a wide frequency range. The interference mechanism and resonance absorption are identified through analytical derivation and numerical simulations. Numerical results show that the absorption at normal incidence is above 90% in the frequency range of 8.37–21 GHz. Moreover, the structure has a thickness of 3.65 mm (only 0.10λ to 0.26λ at the lowest and highest frequencies, respectively). The explanation to the physical mechanism of the metamaterial absorber is presented and verified.
TL;DR: In this paper, a triple-band polarization-independent metamaterial absorber using square-shaped closed ring resonators over wide angle of incidence was proposed for airborne and surveillance radar signal absorption applications.
Abstract: In this paper, we propose a triple band polarization-independent metamaterial absorber using square-shaped closed ring resonators over wide angle of incidence. The unit cell consisting of various square loops is designed by using the parametric analysis so that it exhibits a triple band absorption response with two bands lying in C-band and one in X-band for airborne and surveillance radar signal absorption applications. Furthermore, in X-band, the absorber exhibits a broadband response with full width at half maxima bandwidth of 940 MHz (9.43%). The structure exhibits bandwidth enhanced properties for any angle of polarization under normal incidence. It also shows high absorption for wide angle of incidence up to 60°. The proposed structure is fabricated and experimental results show proper matching with the simulated responses.
TL;DR: In this article, a thermally active superconductor-metal coupled resonator based hybrid terahertz metamaterial was demonstrated on a sapphire substrate that shows tunable transparency and slow light behavior.
Abstract: Structured plasmonic metamaterial devices offer the design flexibility to be size scaled for operation across the electromagnetic spectrum and are extremely attractive for generating electromagnetically induced transparency and slow-light behaviors via coupling of bright and dark subwavelength resonators. Here, we experimentally demonstrate a thermally active superconductor-metal coupled resonator based hybrid terahertz metamaterial on a sapphire substrate that shows tunable transparency and slow light behavior as the metamaterial chip is cooled below the high-temperature superconducting phase transition temperature. This hybrid metamaterial opens up the avenues for designing micro-sized active circuitry with switching, modulation, and “slowing down terahertz light” capabilities.
TL;DR: In this article, the authors investigated the application of metamaterial absorber (MA) to waveguide slot antenna to reduce its radar cross section (RCS) and demonstrated that the monostatic and bistatic RCS of the slot antenna are reduced significantly, and the performance of antenna is preserved simultaneously.
Abstract: This communication investigates the application of metamaterial absorber (MA) to waveguide slot antenna to reduce its radar cross section (RCS). A novel ultra-thin MA is presented, and its absorbing characteristics and mechanism are analyzed. The PEC ground plane of waveguide slot antenna is covered by this MA. As compared with the slot antenna with a PEC ground plane, the simulation and experiment results demonstrate that the monostatic and bistatic RCS of waveguide slot antenna are reduced significantly, and the performance of antenna is preserved simultaneously.
TL;DR: A fully-dielectric metamaterial is experimentally demonstrated that exhibits a 'trapped mode' resonance at optical frequencies, founded upon the excitation by incident light of anti-parallel displacement currents in meta-molecules comprising pairs of parallel, geometrically dissimilar dielectric nano-bars.
Abstract: Optical responses in conventional metamaterials based on plasmonic metal nanostructures are inevitably accompanied by Joule losses, which obstruct practical applications by limiting resonance quality factors and compromising the efficiency of metamaterial devices. Here we experimentally demonstrate a fully-dielectric metamaterial that exhibits a ‘trapped mode’ resonance at optical frequencies, founded upon the excitation by incident light of anti-parallel displacement currents in meta-molecules comprising pairs of parallel, geometrically dissimilar dielectric nano-bars. The phenomenon is demonstrated in the near-infrared part of the spectrum using silicon, showing that in principle strong, lossless resonant responses are possible anywhere in the optical spectral range.
TL;DR: By deliberately controlling the dispersion and dissipation of a metamaterial, an ultrawideband perfect metamMaterial absorber with complex-valued constitutive parameters strictly satisfying the modified model of a perfectly matched layer, can be achieved.
Abstract: Narrow bandwidth is a fundamental issue plaguing practical applications of metamaterial absorbers. In this Letter, we show that by deliberately controlling the dispersion and dissipation of a metamaterial, an ultrawideband perfect metamaterial absorber with complex-valued constitutive parameters strictly satisfying the modified model of a perfectly matched layer, can be achieved. The nearly perfect power absorption, better than 99%, was experimentally observed in an unprecedented bandwidth of 39%, approaching the theoretical Rozanov limit. We expect a wide range of applications to emerge from this general concept.
TL;DR: In this article, a planar array of resonators on a highly elastic polydimethylsiloxane substrate was used to demonstrate mechanically tunable metamaterials operating at terahertz frequencies.
Abstract: Electromagnetic device design and flexible electronics fabrication are combined to demonstrate mechanically tunable metamaterials operating at terahertz frequencies. Each metamaterial comprises a planar array of resonators on a highly elastic polydimethylsiloxane substrate. The resonance of the metamaterials is controllable through substrate deformation. Applying a stretching force to the substrate changes the inter-cell capacitance and hence the resonance frequency of the resonators. In the experiment, greater than 8% of the tuning range is achieved with good repeatability over several stretching-relaxing cycles. This study promises applications in remote strain sensing and other controllable metamaterial-based devices.
TL;DR: In this article, a multi-layered stacked metamaterial is compared and shown to be superior to another approach to multiple-band perfect absorbers having closely packed resonators within a unit cell.
Abstract: Simple periodic structures of stacked metal and dielectric microdisks can display very high absorbance over multiple bands at infrared frequencies (3–10 μm wavelengths). The stack can be envisaged as intersecting tri-layers, each tri-layer composed of metal–dielectric–metal disks that form independent impedance matched resonators, and give rise to large absorbance at different frequencies. Numerical simulations show that dual-band and multi-band absorbers with near unity absorbance on all their bands can be flexibly designed whereby the dielectric materials determine the absorption band of the metamaterial. The multi-band absorber is reasonably polarization insensitive and the absorbance remains large even with large angles of incidence. This approach of multi-layered stacked metamaterials is compared and shown to be superior to another approach to multiple-band metamaterial perfect absorbers having closely packed resonators within a unit cell.
TL;DR: Here, an alternative approach for constructing metamaterials with extreme dispersion is demonstrated by simply coiling up space with curled channels, leading to a clear demonstration of negative refraction from an acoustic meetamaterial with airborne sound.
Abstract: Metamaterials are effectively homogeneous materials that display extraordinary dispersion. Negative index metamaterials, zero index metamaterials and extremely anisotropic metamaterials are just a few examples. Instead of using locally resonating elements that may cause undesirable absorption, there are huge efforts to seek alternative routes to obtain these unusual properties. Here, we demonstrate an alternative approach for constructing metamaterials with extreme dispersion by simply coiling up space with curled channels. Such a geometric approach also has an advantage that the ratio between the wavelength and the lattice constant in achieving a negative or zero index can be changed in principle. It allows us to construct for the first time an acoustic metamaterial with conical dispersion, leading to a clear demonstration of negative refraction from an acoustic metamaterial with airborne sound. We also design and realize a double-negative metamaterial for microwaves under the same principle.
TL;DR: In this paper, two or four gold cross resonators with different sizes are multiplexed in a unit cell on SiO(2) spacing layer on top of gold ground plane.
Abstract: In this paper, we theoretically and experimentally demonstrate broadband metamaterial absorbers that work in the mid-infrared regime. In the absorbers, two or four gold cross resonators with different sizes are multiplexed in a unit cell on SiO(2) spacing layer on top of gold ground plane. Compared with the single cross resonator absorbers with a Q factor of 6.39, the developed absorber with two cross resonators multiplexed reduces the Q factor to 3.78. When four different cross resonators are integrated, the Q factor drops to as low as 1.85, and the bandwidth almost covers the full mid-infrared regime from 3 μm to 5 μm with absorbance higher than 50%.
TL;DR: A new type of absorber, a four-tined fish-spear-like resonator (FFR), constructed by the two-photon polymerization process, is reported that is perfectly thermo- and electroconductive, which is the mostly desired feature for many applications.
Abstract: A new type of absorber, a four-tined fish-spear-like resonator (FFR), constructed by the two-photon polymerization process, is reported. An absorbance of more than 90% is experimentally realized and the resonance occurs in the space between the tines. Since a continuous layer of metallic thin film covers the structure, it is perfectly thermo- and electroconductive, which is the mostly desired feature for many applications.
TL;DR: In this paper, the authors embed diodes as active circuit elements within a metamaterial to implement a switchable reflector/absorber at microwave frequencies, which can be tuned on and off to switch the function between a perfect absorber and a reflector.
Abstract: We embed diodes as active circuit elements within a metamaterial to implement a switchable metamaterial reflector/absorber at microwave frequencies. Diodes are placed in series with the unit cells of the metamaterial array. This results in just a pair of control lines to actively tune all the diodes in a metamaterial. Diodes can be tuned on and off to switch the function of the metamaterial between a perfect absorber and a reflector. The design, simulation, and experimental results of a switchable reflector/absorber in 2–6 GHz range are presented.
TL;DR: In this article, near-perfect IR light absorption at multiple wavelengths has been experimentally demonstrated by using multiplexed metal square plasmonic resonance structures, where the peak absorption wavelengths are primarily determined by the sizes of the metal squares in the multiplexing structures.
Abstract: Near-perfect IR light absorption at multiple wavelengths has been experimentally demonstrated by using multiplexed metal square plasmonic resonance structures. Optical power absorption over 95% has been observed in dual-band metamaterial absorbers at two separate wavelengths, and optical power absorption over 92.5% has been observed in triple-band metamaterial absorbers at three separate wavelengths. The peak absorption wavelengths are primarily determined by the sizes of the metal squares in the multiplexed structures. Electrical field distributions in the middle of the dielectric spacer layer were calculated at the peak absorption wavelengths. It is found that the strong light absorption corresponds to local quadrupole plasmon resonance modes in the metamaterial structures.
TL;DR: In this paper, the authors present the design and experimental implementation of a power harvesting metamaterial and demonstrate that the maximum harvested power occurs for a resistive load close to 70 Ω in both simulation and experiment.
Abstract: We present the design and experimental implementation of a power harvesting metamaterial. A maximum of 36.8% of the incident power from a 900 MHz signal is experimentally rectified by an array of metamaterial unit cells. We demonstrate that the maximum harvested power occurs for a resistive load close to 70 Ω in both simulation and experiment. The power harvesting metamaterial is an example of a functional metamaterial that may be suitable for a wide variety of applications that require power delivery to any active components integrated into the metamaterial.
TL;DR: A novel planar plasmonic metamaterial for electromagnetically induced transparency and slow light characteristic is presented in this paper, which consists of nanoring and nanorod compound structures.
Abstract: A novel planar plasmonic metamaterial for electromagnetically induced transparency and slow light characteristic is presented in this paper, which consists of nanoring and nanorod compound structures. Two bright modes in the metamaterial are induced by the electric dipole resonance inside nanoring and nanorod, respectively. The coupling between two bright modes introduces transparency window and large group index. By adjusting the geometric parameters of metamaterial structure, the transmittance of EIT window at 385 THz is about 60%, and the corresponding group index and Q factor can reach up to 1.2 × 10³ and 97, respectively, which has an important application in slow-light device, active plasmonic switch, SERS and optical sensing.
TL;DR: In this paper, a polarization-independent tunable absorbing metamaterial (MM) was designed in the mid-infrared wavelength regime. Butt et al. showed that a 10% tuning of the absorbance peak can be obtained by switching the phase change material (PCM) between amorphous and crystalline states.
Abstract: We present the design of a polarization-independent tunable absorbing metamaterial (MM) in the mid-infrared wavelength regime. Our structure is composed of an array of thin gold (Au) squares separated from a continuous Au film by a phase-change material (PCM) layer. It is shown that a 10% tuning of the absorbance peak can be obtained by switching the PCM between its amorphous and crystalline states. The strong absorbance shows a substantial overlap between TE and TM polarization states over a wide range of incident angles. The electric field, magnetic field, and current distributions in the absorber are investigated to further explain the physical origin of the absorption. The study provides a path toward the realization of tunable absorbers for applications, such as selective thermal emitters, sensors, and bolometers.
TL;DR: The use of single-sized "meta-cells" to achieve multiple absorption peaks and the use of a thin-flexible dielectric spacer makes it promising for stealth technology applications in order to disguise objects and make them less visible to radar and other detection methods.
Abstract: Standard optical lithography relying on clean room and microelectronic facilities is used to fabricate a thin-flexible metamaterial absorber, designed to operate at submillimeter wavelengths over the 0.1-1 THz frequency band. Large terahertz absorption has been demonstrated numerically and through experimental measurements with a maximum level of about 80%. We put emphasis in this present work on the use of single-sized "meta-cells" to achieve multiple absorption peaks. Furthermore, the use of a thin-flexible dielectric spacer makes it promising for stealth technology applications in order to disguise objects and make them less visible to radar and other detection methods.
TL;DR: A theory of perfect absorption in a bilayer model composed of a mu-near-zero (MNZ) metamaterial absorbing layer on a metallic substrate is presented and a microwave absorber using double-layered spiral MMs with a thickness of only about one percent of the operating wavelength is designed and realized.
Abstract: We present a theory of perfect absorption in a bilayer model composed of a mu-near-zero (MNZ) metamaterial (MM) absorbing layer on a metallic substrate. Our analytical solutions reveal that a MM layer with a large purely imaginary permeability and a moderate permittivity backed by a metallic plane has a zero reflection at normal incidence when the thickness is ultrathin. The impedance-mismatched metamaterial absorber (MA) can be 77.3% thinner than conventional impedance-matched MAs with the same material loss in order to get the same absorption. A microwave absorber using double-layered spiral MMs with a thickness of only about one percent of the operating wavelength is designed and realized. An absorption efficiency above 93% at 1.74 GHz is demonstrated experimentally at illumination angles up to 60 degrees. Our absorber is 98% lighter than traditional microwave absorbers made of natural materials working at the same frequencies.
TL;DR: In this article, a broadband THz absorber with an array of graphene-dielectric multilayered frustum pyramids on a metal sheet is introduced, which can be considered an effectively homogeneous metamaterial with an hyperbolic dispersion and anisotropic permittivity.
Abstract: We introduce a broadband THz absorber with an array of graphene-dielectric multilayered frustum pyramids on a metal sheet. The multilayered graphene-dielectric structure can be considered an effectively homogeneous metamaterial with an hyperbolic dispersion and anisotropic permittivity. Surface plasmonic waves are excited on graphene layers and the incident waves of different frequencies are absorbed at different levels of the stacked pyramid, due to the squeezing effect of the slow waves at the tapered waveguide. An absorption dip is observed and explained physically, and finally removed by adding a rectangular portion to the pyramid unit cell. High absorption with an extremely broad bandwidth from 8 THz to over 100 THz is achieved. The absorption spectrum of the present structure can be scaled down to a lower frequency (e.g. 2 THz) by increasing the size of the unit cell.
TL;DR: In this article, a terahertz metamaterial absorber (MA) based on a periodic array of square copper films was investigated numerically, and the absorption of the composite structure MA is greater than 90% and near perfect impedance-match to the free space in the frequency ranges of 6.24-7.04 THz.
Abstract: A simple design of terahertz metamaterial absorber (MA) based on a periodic array of square copper films was investigated numerically. The perfect narrow absorption mainly originates from magnetic polariton excitation and perfect impedance-match. The perfect absorbing properties of this simple design could be tunable by changing the side length based on equivalent LC resonance circuit mode. The bandwidth of the perfect absorption can be effectively enhanced by simply patterning different dimension elements with appropriate geometrical parameters on a coplanar. Finally, the absorption of the composite structure MA is greater than 90% and near perfect impedance-match to the free space in the frequency ranges of 6.24–7.04 THz. Further numerical simulations also demonstrate that the MA could achieve very high absorptivity at wide angles of incidence and polarization for both TE and TM waves.