- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 12th International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials) - Espoo, Finland (2018.8.27-2018.9.1)] 2018 12th International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials) - General Conditions to Realize Exceptional Points of Degeneracy and Applications
摘要： We explore the emergence of exceptional points of degeneracy (EPDs) that denote a coalescence of multiple eigenmodes in coupled-mode structures. We establish the general conditions that lead to observing EPDs of different orders in various coupled systems, either uniform (non-periodic) or periodic. EPDs can be found in lossless systems as well as in systems with gain-loss balance. Also, we provide examples of potential applications of structures with EPDs that help improve the performance of devices, like sensors, oscillators, etc., at microwave and optical frequencies.
关键词： exceptional points of degeneracy,optical frequencies,microwave frequencies,EPDs,gain-loss balance,oscillators,lossless systems,coupled-mode structures,sensors
更新于2025-09-23 15:21:21
-
Tunable quad-band transmission response, based on single-layer metamaterials
摘要： We investigated the electromagnetically induced transparency (EIT)-like effects in planar metamaterials (MMs) at microwave (GHz) frequencies. The specific MMs that were used in this study consist of cut-wire resonator/ring resonator, which achieved the dual EIT-like effects in a single-layer through the bright- and quasi-dark-mode coupling and the lattice mode coupling. In addition, by varying the distance between the two resonators, the quad-band EIT spectral response in the microwave region was obtained, and the group refractive index at the EIT-like resonance of proposed design reached up to 4,000. This study provides the design approach to the multispectral EIT-like effects and might suggest potential applications in a variety of fields, for example, low-loss slow-light device, multiple switching sensor, and other sensing devices.
关键词： microwave frequencies,slow-light device,quad-band transmission,electromagnetically induced transparency,metamaterials
更新于2025-09-23 15:21:01
-
A Band-Pass Filter Based on Half-Mode Substrate Integrated Waveguide and Spoof Surface Plasmon Polaritons
摘要： In this paper, a band-pass filter based on half-mode substrate integrated waveguide (HMSIW) and double-layer spoof surface plasmon polaritons (SSPPs) consisting of two corrugated metal strips is proposed, which can realize band-pass transmission by etching periodic grooves at the top and bottom metal layers of the HMSIW. Moreover, the influences of important parameters on the performance of the proposed band-pass filter are analyzed by parametric study. By changing the key parameters, the low and high cut-off frequency can be controlled independently. The corresponding equivalent circuit of the proposed band-pass filter is put forward to explain the physical mechanism. Compared with the previous structures, this structure features smaller size, wider bandwidth and lower loss. Simulated results show that the proposed band-pass filter achieves a bandwidth (for |S11| < ?10 dB and |S21| > ?0.8 dB) of about 69.77% (15.6–32.1 GHz). The measured results have good agreements with the simulated ones, which verify that the proposed band-pass filter has good performances and potential applications at the microwave frequencies.
关键词： microwave frequencies,band-pass filter,spoof surface plasmon polaritons,half-mode substrate integrated waveguide
更新于2025-09-12 10:27:22
-
Capacitor-Inspired Metamaterial Inductors
摘要： In optical metatronics, where properly designed nanostructures function as lumped optical circuit elements, the capacitive and inductive optical circuit elements are nanostructures with positive and negative real parts of the permittivity of their materials, respectively. Aside from this difference in material properties, other features such as shapes and dimensions of these two elements may be similar. In the rf and microwave domains, however, conventional capacitors and inductors have vastly different features, i.e., one is made of parallel plates and the other is formed by wound wires. Here, inspired by optical metatronics, we propose to bring the notion of optical metatronics back into the low-frequency domain, by suggesting a capacitorlike structure that behaves as an inductive circuit element at microwave frequencies. This simple design may be achieved by adding certain sidewalls in the capacitor structure, and thus its shape is different from conventional inductors made of wires and spirals. The approximate range of inductance can be conceptually evaluated using relations analogous to those of the capacitance. Using numerical and analytical methods, we determine its complex impedance and quality factor as a function of frequency and all the dimensional parameters involved. From this analysis, we find that as compared with a conventional inductor this structure may have certain advantages, which include a higher quality factor due to its approximately closed structure and strong dependence of its inductance value on its height with weaker dependence on its cross section. We also study a subwavelength resonator using our proposed structure as its inductive element, confirming its performance numerically.
关键词： subwavelength resonator,microwave frequencies,optical metatronics,quality factor,capacitor-inspired metamaterial inductors
更新于2025-09-11 14:15:04
-
[IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz2018) - Nagoya, Japan (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Intrinsic Losses in Dielectrics Investigated by Terahertz Spectroscopy
摘要： Low-loss dielectrics with various microstructure and, consequently, different extrinsic losses were investigated by using terahertz time-domain spectroscopy. The losses have been extrapolated and compared with those measured at microwave frequencies. The results showed that extrinsic factors have a considerably contribution in microwave domain. The intrinsic limit of dielectric loss of low absorption polycrystalline materials have been estimated by terahertz spectroscopy.
关键词： microwave frequencies,intrinsic losses,terahertz spectroscopy,extrinsic losses,dielectrics
更新于2025-09-10 09:29:36