Numerical investigation of Fano resonances in metamaterials with electric asymmetry

Rotaru, Mihai; Sykulski, J.K.

doi:10.1049/iet-smt.2011.0111

Cited by 4 publications

(2 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Theoretical Prediction of Probe Material Properties : The ceramic probe was modeled by a high‐permittivity, low‐loss dielectric resonator in its TE 01 δ eigenmode. Due to its properties and symmetries, its TE 01 δ mode field distribution is analytically described using Bessel functions (Equations (1) to (3), Supporting Information) . The TE 01 δ eigenmode exists for disk as well as for ring resonators (with very similar field distributions as long as the ring inner radius is not too large).…”

Section: Methodsmentioning

confidence: 99%

Systematic Analysis of the Improvements in Magnetic Resonance Microscopy with Ferroelectric Composite Ceramics

et al. 2019

View full text Add to dashboard Cite

small specimens as single cells, [2] single neurons, [3][4][5] and myofibers, [6] and even functional investigation of such samples. [7] Although the ultimate limit to spatial resolution in MRM is the diffusion of water within the finite measuring time, the practical limit is the achievable signal-tonoise ratio (SNR) per unit voxel in a given data acquisition time. [1,8] MRM is performed at very high B 0 with compact radiofrequency coils (called probes) typically operating both in transmission and reception modes. The probes should be made as close-fitting as possible for a given sample to maximize the SNR and, therefore, attainable image spatial resolution. [8] As the noise is generated by both the probe and the sample, reducing the probe losses and the electric-field-mediated coil-sample interactions is very desirable. [9] Cooling the probe down to cryogenic temperatures allows operation in a mode in which the noise is dominated by the sample. Several authors reported an approximately twofold increase in SNR when studying biological samples compared to using conventional copper coils. [10,11] The disadvantage of all cryogenic probes is that they are much more difficult to fabricate and provide limited access to the sample as well as a lower filling factor.The spatial resolution and signal-to-noise ratio (SNR) attainable in magnetic resonance microscopy (MRM) are limited by intrinsic probe losses and probe-sample interactions. In this work, the possibility to exceed the SNR of a standard solenoid coil by more than a factor-of-two is demonstrated theoretically and experimentally. This improvement is achieved by exciting the first transverse electric mode of a low-loss ceramic resonator instead of using the quasi-static field of the metal-wire solenoid coil. Based on theoretical considerations, a new probe for microscopy at 17 T is developed as a dielectric ring resonator made of ferroelectric/dielectric low-loss composite ceramics precisely tunable via temperature control. Besides the twofold increase in SNR, compared with the solenoid probe, the proposed ceramic probe does not cause static-field inhomogeneity and related image distortion. Ceramics for Improved Microscopy

show abstract

Section: Methodsmentioning

confidence: 99%

Systematic Analysis of the Improvements in Magnetic Resonance Microscopy with Ferroelectric Composite Ceramics

et al. 2019

View full text Add to dashboard Cite

show abstract

“…9) except for the anomalous peak at 11.2 GHz. This peak is caused by a Fano resonance, which could also be modeled, although it would require the use of two coupled RLC resonators [30], what is beyond the scope of this paper.…”

Section: B Lossy Scatterer With a Symmetry Planementioning

confidence: 99%

Equivalent-Circuit Modeling of Lossless and Lossy Bi-Periodic Scatterers by an Eigenstate Approach

Hernández-Escobar

Esteban²,

Abdo-Sánchez

et al. 2022

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

The use of an eigenstate based equivalent circuit topology is proposed for the analysis and modeling of lossless and lossy bi-periodic scatterers. It can significantly simplify the design of this kind of surfaces, since it reduces the number of elements with respect to other general circuits. It contains at most only two admittances and two transformers depending on one unique transformation ratio. The real parts of these admittances can be assured to be non-negative, an interesting aspect in the modeling of lossy surfaces such as those present in asorbers. Moreover, due to the capability of decomposition into the eigenexcitations of the structure, the circuit provides important physical insight. Different cases of scatterers have been analyzed: symmetric and asymmetric, lossy and lossless. In all these cases, the modeling of the circuit admittances has been successfully achieved with a few RLC elements, positive and frequency independent. In the case of structures with symmetries, the transformation ratio directly reflects the physical orientation of the eigenexcitations of the scatterer. Furthermore, in the case of lossy scatterers but without symmetries, the resulting equivalent circuit reveals that their eigenexcitations are not linear polarizations, but elliptic polarizations whose properties are described by the complex transformation ratio.

show abstract

Slow Wave Applications of Electromagnetically Induced Transparency in Microstrip Resonator

Amin

Ramzan

Siddiqui

2018

Sci Rep

View full text Add to dashboard Cite

We report a novel guided-wave resonator that supports multiple bands of electromagnetically induced transparency (EIT). The platform for the spatial and spectral interference is obtained by a microstrip transmission line loaded with proximity-coupled open-circuited stubs. We show experimentally that with two microstrip open stubs, a complete destructive interference takes place leading to a single EIT band with near-unity transmission efficiency. More interestingly, the addition of a third stub results in a supplementary EIT band with a Q-factor of 147 and an effective group refractive index of 530. With the open-stub configuration, the EIT phase response can be dynamically controlled by varying the capacitance between the adjacent stubs without breaking the transmission path of the underlying electromagnetic waves. Therefore, the proposed structure is well suited for buffering and tunable phase modulation applications. Since the proposed structures are compact and fully planar, we anticipate seamless integration with low-profile high frequency electronics.

show abstract

Numerical investigation of Fano resonances in metamaterials with electric asymmetry

Cited by 4 publications

References 7 publications

Systematic Analysis of the Improvements in Magnetic Resonance Microscopy with Ferroelectric Composite Ceramics

Systematic Analysis of the Improvements in Magnetic Resonance Microscopy with Ferroelectric Composite Ceramics

Equivalent-Circuit Modeling of Lossless and Lossy Bi-Periodic Scatterers by an Eigenstate Approach

Slow Wave Applications of Electromagnetically Induced Transparency in Microstrip Resonator

Contact Info

Product

Resources

About