Electric Inductive-capacitive Resonator Research Articles

Novel Octa-Structure Metamaterial Architecture for High Q-Factor and High Sensitivity in THz Impedance Spectroscopy.

Terahertz (THz) electric inductive-capacitive (ELC) resonant metamaterials (MMs) are well established tools that can be used to detect the presence of dielectric material (e.g., nanoparticles, bioparticles, etc.) spread on their surfaces within the gap of the capacitive plates of a nanoantenna array. In THz spectroscopy, the amount of the red shift in the resonance frequency (ΔF) plays an important role in the detection of nanoparticles and their concentration. We introduce a new LC resonant MM architecture in the ELC category that maximizes dielectric sensitivity. The newly proposed architecture has an octahedral structure with uniform capacitive gaps at each forty-five-degree interval, making the structure super-symmetric and polarization independent. The inductor core is condensed into a central solid circle connecting all the eight lobes of the octahedron, thereby completing the LC circuit. This ELC resonator has very large active areas (capacitor-gaps), with hotspots at the periphery of each unit cell. The MM structure is repeated in a clustered fashion, so that the peripheral hotspots are also utilized in dielectric sensing. This results in enhancing the quality factor of MM resonance, as well as in increasing ΔF. The research comprises a combination of rigorous system-level simulations along with THz impedance spectroscopy laboratory experiments. We achieved a highly sensitive MM sensor with sensitivity reaching 1600 GHz/RIU. This sensor is fully CMOS compatible and has promising potential applications in high-sensitivity bio-sensing, characterization of nanoparticles, and ultra-low-concentration dielectrics detection, as well as in sensing differential changes in the composition of substances deposited on the metasurface.

Dual Band Metasurface Integrated With Wideband Power Combiner for RF Energy Harvesting

This letter presents a novel dual-band metasurface (MS) structure with a Chebyshev transformer-based wideband power combiner for RF energy harvesting (RFEH). The unit cell (UC) of MS formed by embedding an electric-inductive capacitive resonator (EICR) in a single square loop (SSL) provides dual-band characteristics at 2.2 and 4.6 GHz, respectively. The wideband power combiner in corporate feed architecture, represented by the circuit schematic, channels the power to a 50- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega$</tex-math> </inline-formula> load, mimicking the input impedance of any standard rectifier. The system is studied using numerical simulation followed by fabrication of the prototype and its validation with experiment. The proposed system provides close to 90% radiation to ac conversion efficiency at 50- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega$</tex-math> </inline-formula> load in dual-band.

Utilization of Shorted Fractal Resonator topology for high isolation and ELC resonator for band suppression in compact MIMO UWB antenna

A low profile modified Koch fractal shaped boundary, ultrawideband (UWB) multiple input multiple output (MIMO) antenna is presented. The radiators are elliptically tapered from the feed line with triangular shaped loading. The boundaries of the triangular shaped loading are embedded with modified Koch fractal shape to provide improved impedance matching. A band suppression characteristic at 5.5 GHz is incorporated by using an electric inductive capacitive resonator at the back of the substrate. Enhanced port isolation of <−20 dB is achieved by using a Maple leaf fractal structure shorted with ground plane. The proposed UWB MIMO antenna has peak realized gain of 4 dBi, and envelope correlation factor is less than 0.01. Measured results closely resemble the simulated results. Moreover, an equivalent circuit model of the proposed structure is extracted and compared with the em simulation result, which are in good agreement.

Mutual coupling reduction in metamaterial antenna for terahertz application

We investigate in this work an effective approach to reduce mutual coupling between two metamaterial antennas operating at the THz frequency band by incorporating a metasurface designed using an electric inductive capacitive resonator. The metasurface is designed to provide a band stop functionality in the operating bandwidth of the antenna. The proposed method shows that the improvement of mutual coupling is at least 10 dB compared with conventional antennas. Thus, this proposed approach can be utilized to mitigate mutual coupling between antennas in THz application. Moreover, to enhance the antenna performances in terms of return loss, directivity, gain, and radiation efficiency, the antenna is designed with a mushroom structure based on the zeroth-order resonant characteristic of a composite right/left-handed transmission line. The electromagnetic behavior of the antenna is studied and an analytical equivalent-circuit model is also proposed.

Pattern and frequency reconfigurable antenna with diode loaded ELC resonator

AbstractIn this work, a new compact, low profile, frequency, and end-fire pattern reconfigurable antenna is presented. The proposed antenna consists of four parasitic elements and an electric-inductive-capacitive (ELC) resonator enclosed with a closed ring resonator (CRR). The reconfigurability in the proposed antenna is achieved with the help of five PIN diodes (D1–D5) embedded on the top surface of the substrate. The diode (D1) is implanted between ELC and CRR resonators for frequency reconfigurability. The other four diodes (D2–D5) are implanted between the ground plane and four parasitic elements to control the electrical length of the ground plane to achieve pattern diversity. The ground plane and parasitic elements steer the primary omni-directional beam to bi-directional and uni-directional end-fire radiation at multiple frequencies. The proposed antenna exhibits multiband operation and end-fire pattern diversity depending upon the different states of PIN diodes. The overall size of the proposed antenna is 0.20λ0× 0.17λ0× 0.009λ0, where λ0 is calculated at the lowest resonance frequency. The impedance bandwidth of the antenna ranges from 1.45 to 26.22%, while peak gain varies from 0.86 to 3.86 dBi depending upon the state of operation. The measured results are in agreement with the simulated results, which confirm the frequency and pattern diversity performance of the antenna. The proposed antenna can be used in back-to-back repeater systems.

Improved design of CELC meta-resonators for bandwidth improvement and miniaturization of patch antenna

For metamaterial resonators, the essential figure of merit is its effective medium ratio (EMR), which is defined as the ratio of the resonant wavelength and lattice constant. In this paper, an altered topology of the electric-inductive–capacitive (ELC) metamaterial with an improved EMR is proposed. The proposed structure shrinks the electrical footprint of the conventional ELC resonator by accommodating additional inductance by meandering the arms of the resonator and fitting interdigital capacitors in the capacitive gap. The metamaterial properties of the proposed structure are investigated by parameter extraction, and analytical formulations are carried out for finding its resonant frequency. The proposed metamaterial structure is employed for performance enhancement and miniaturization of a standard patch antenna. A 3 × 4 array of the modified complementary resonators is etched in the ground plane of a patch antenna. A significant 293% improvement in bandwidth, with a miniaturization factor (unloaded frequency/loaded frequency) of 1.33 is achieved. The entire antenna resides in a small area of 37.5 mm × 37.5 mm. The design is substantiated both by simulation and experimental results, which complement each other. The presented design can be used for Mobile WiMAX (2.5–2.69 GHz) applications.

Dual-band monopole antenna loaded with ELC metamaterial resonator for WiMAX and WLAN applications

In this paper, a miniaturized ELC (Electric-inductive-capacitive) based dual-band antenna is proposed for WiMAX and WLAN Applications. The designed antenna consists of a ring monopole antenna coupled with ELC resonator and partial rectangular ground plane, which is fed by 50Ω microstrip transmission line. ELC metamaterial modifies the current direction and yields dual-band characteristics. The band characteristics of the ELC metamaterial element are explained in detail. The proposed antenna with a compact size of 30 $$\times$$ 30 $$\times$$ 0.8 mm3 is fabricated on a FR-4 substrate of thickness of 0.8 mm, with relative dielectric constant $${{\mathbf{\varepsilon }}_{\mathbf{r}}}$$ = 4.4 and loss tangent $$\tan \varvec{\delta}$$ = 0.002. The experimental results cover the bandwidth of 500 MHz (3.57–4.04 GHz) and 860 MHz (4.73–5.59 GHz) with a resonance frequency of 3.74 and 5.1 GHz, respectively, which is suitable for WiMAX and WLAN applications.

A Mirror Shape Chiral Meta Atom for C-Band Communication

This paper reports that a miniaturized chiral meta-atom has 5.14-GHz bandwidth and applicable for $C$ -band applications. The meta-atom is developed by an electric inductive-capacitive resonator, where the inverse E-shape structure is combined with the outer ring resonator. The dimension of the proposed single unit cell structure is $6.0\times 6.0$ mm2 that is printed on a Rogers RT 5880 material. Finite integration technique-based CST Microwave Studio has been utilized to design, simulation, and investigation purposes. An Agilent N5227A vector network analyser is used to retrieval the effective parameters and the measured and simulated results are well arranged together. The negative refraction bandwidth of 5.14 GHz (from 4.0 to 9.14 GHz) and the effective medium ratio 6.96 make the designed meta-atom is suitable for practical applications.

ELC metamaterial based CPW‐fed printed dual‐band antenna

ABSTRACTThis letter presents metamaterial (MTM) based dual band antenna. Two resonances are obtained by making use of square ELC (Electric‐inductive‐capacitive) resonator and CR (Closed Ring) resonator. This research evolves an antenna having dimension only of 21 × 30 × 1.6 mm3 which operates at two bands from 3.28 GHz to 4.52 GHz and from 5.20 GHz to 5.87 GHz. This antenna can be useful for WiMAX and WLAN transceiver at 3.5 GHz and 5 GHz band respectively. It can also be used in RFID applications at 3.9 GHz band. This paper includes the parametric investigations as well as measurement details. Simulation and measurement data have shown good equivalence which emphasis the practicability of the proposed antenna. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:304–307, 2017

Rapid microwave phase detection based on a solid state spintronic device

A technique for rapidly detecting microwave magnitude and phase has been developed using a spintronic device as a microwave sensor, which allows a lock-in amplifier to perform real-time microwave measurement. To demonstrate the feasibility and reliability of the proposed approach, the resonance including the amplitude and phase in a complementary electric inductive-capacitive resonator has been characterized. The results are in agreement with measurement preformed by a vector network. This sensor approach is not limited for use only with spintronic devices, but can also be used with semiconductor devices and hence offers a useful alternative to existing microwave imaging and characterization technologies.

A Design Procedure for Electric Inductive Capacitive Resonators with Negative Permittivity

Permittivity signifies a key component to metamaterial which can achieve negative index of refraction, but it has not been sufficiently addressed in computational design. This paper aims to attain negative permittivity through a topology optimization approach and provides an example equivalent to electric inductive-capacitive resonator. Similar to split ring resonator, this locally self-contained (without the demand for inter-cell connection) resonator allows keeping bulk electromagnetic properties homogeneously, facilitating mass fabrication, and realizing single sampling test.

Resonant mode behavior of lumped-resistor-loaded electric-inductive-capacitive resonator and its absorber application

This paper presents investigations into the resonant mode behavior of a lumped-resistor-loaded electric-inductive-capacitive (ELC) resonator, which is illuminated with a parallel polarization external electromagnetic wave. An ELC resonator exhibits a negative effective permittivity for both parallel and perpendicular polarizations. In contrast to a common ELC resonator, the lumped-resistor-loaded ELC resonator exhibits a switchable resonant mode behavior, thereby revealing a negative effective permeability. In addition, this resonator exhibits a low quality factor owing to the loaded lumped resistors. A metamaterial absorber, which consists of a lumped-resistor-loaded ELC resonator and a cut-wire strip, is designed to confirm the effectiveness of the resonator.

Hilbert-Shaped Magnetic Waveguided Metamaterials for Electromagnetic Coupling Reduction of Microstrip Antenna Array

A novel single-negative magnetic waveguided metamaterial (MTM) is initially proposed based on the Hilbert-shaped complementary electric inductive-capacitive resonator. The MTM element is highly compact due to the Hilbert space-filling curves which considerably enhance the current path in the ground, and exhibits a bandgap attributing to the negative permeability in the vicinity of magnetic resonance. Taking the advantage of these two features, a microstrip antenna array is then designed, fabricated, and measured by embedding a 5×1 array of the well-engineered MTM elements between two closely spaced (λ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</i> /8.08) H-plane coupled rectangular patches. Both numerical and experimental results indicate a mutual coupling reduction of more than 9.7 dB. The proposed prescription with electrically small dimensions and high decoupling efficiency opens an avenue to new types of antennas with super performances.

Near-field interactions in electric inductive–capacitive resonators for metamaterials

Near-field interactions in an array of electric inductive–capacitive (ELC) resonators are investigated analytically, numerically and experimentally. The measurement and simulation results show that inter-cell coupling plays an important role in determining the response of metamaterials. A quasistatic dipole–dipole interaction model, together with a Lagrangian formalism, quantitatively explains the interplay between the electric and magnetic couplings in the resonator array. Depending on the alignment of the resonators, the couplings can cause resonance shifting and/or splitting. The knowledge obtained from this study is crucial in designing metamaterials with ELC resonators.

Harmonic suppressed bandpass filter using composite right/left handed transmission line

A wideband composite right/left handed transmission line (CRLH TL) in conjunction with its corresponding equiva-lent circuit model is studied based on a cascaded complementary single split ring resonator (CCSSRR). The characterization is performed by theory analysis, circuit simulation, and full-wave electromagnetic (EM) simulation. The negative refractive index (NRI) and backward wave propagation performance of the CRLH TL are demonstrated. For application, a bandpass filter (BPF) with enhanced out-of-band selectivity and harmonic suppression operating at the wireless local area network (WLAN) band is designed, fabricated, and measured by combining the CRLH TL with a complementary electric inductive-capacitive resonator (CELC). Three CELC cells with wideband stopband performance in the conductor strip and ground plane, respectively, are utilized in terms of single negative permeability. The design concept has been verified by the measurement data.

Analytically describing the temperature-dependent constitutive parameters of an electromagnetic metamaterial

Analogous to mechanical systems, modeling the electromagnetic (EM) performance of large and complex metamaterial structures requires the use of effective-medium/constitutive properties. Constitutive properties are critical for efficiently bridging the gap between subwavelength geometry and performance at the mesoscale. In this article, the temperature-dependent effective medium properties for a metamaterial electric-inductive-capacitive (ELC) resonator are described analytically. ELC structures are commonly used in metamaterial designs to provide a tailored electric response to EM waves. An equivalent circuit model, coupled with analytic expressions for the capacitances, inductance, and resistance of the ELC resonator, is utilized to describe how thermally induced mechanical strain and changes in material properties manifest as temperature-dependent permittivity and permeability curves for the metamaterial. The resulting analytic expressions account for the effects of spatial dispersion and losses. This article also details how the process may be expanded to similarly describe the temperature-dependent constitutive properties of metamaterial magnetic resonators.

Complementary metamaterial transmission line for monoband and dual-band bandpass filters application

A novel composite right-/left-handed transmission line (CRLH TL) and its equivalent circuit model are proposed based on cascaded complementary single split ring resonator (CCSSRR). It features an intrinsically balanced wider band and an additional transmission zero above the right-handed band relative to CRLH TL using complementary single split ring resonator and complementary split ring resonators. Moreover, two single negative (SN) metamaterial (MTM) TLs constructed by using complementary electric inductive-capacitive resonator on the conductor strip and on the ground, respectively, are researched. Both SN MTM TLs exhibit electric resonance above the fundamental magnetic resonance. For application, a monoband (MB) bandpass filter (BPF) covered WLAN band, and a dual-band (DB) BPF covered satellite DMB band and WiMAX band are designed, fabricated, and measured. The SN MTM TLs are adopted for the sake of deep and wide out-of-band suppression while CRLH MTM TLs using square-shaped and Sierpinski-shaped CCSSRR are critical factors of the MB and DB behavior. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012. © 2012 Wiley Periodicals, Inc.

RF Limiter Metamaterial Using p-i-n Diodes

We present the design and experimental implementation of an RF limiter metamaterial using a sheet of nonlinear metamaterials. We demonstrate that complementary electric inductive-capacitive resonators loaded with nonlinear p-i-n diodes can act as RF limiter unit cells. We design and fabricate limiter metamaterials and compare them to traditional circuit limiters. Our limiter metamaterial exhibits a minimum insertion loss under 3 dB, a maximum decrease in transmission of 6.95 dB and broadband performance, with a minimum decrease in transmission of 3 dB over 18% bandwidth. The limiter metamaterial is suitable for a wide variety of practical applications requiring protection of sensitive devices from high power.

FRACTAL-SHAPED COMPLEMENTARY ELECTRIC-LC RESONATOR FOR BANDSTOP FILTER

An equivalent circuit model for single negative metama- terial (MTM) transmission line based on microstrip complementary electric inductive-capacitive resonator (CELC) is proposed for the flrst time. The verifled circuit model gives strong support to the interpreta- tion of all exhibited electromagnetic (EM) phenomena. The nonpure magnetic and electric resonances have been demonstrated by consti- tutive EM parameters. Based on the conclusions that have drawn, a more compact sub-wavelength particle based on Hilbert-shaped CELC (H-CELC) is proposed. The design procedures of the H-CELC-loaded MTM cell are derived based on the circuit model. For application, a bandstop fllter covering one of the ISM bands 5.2GHz by cascading two H-CELC cells is designed, fabricated and measured. Consistent results between simulation and measurement have conflrmed the de- sign. The established theory based on the proposed circuit model is of reference value for the design of novel bandstop devices.