- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Design and characterization of the double-layered defected ground structure transmission line with less radiation loss
摘要： A double-layered DGS transmission line is proposed with a smaller DGS size and less radiation loss. Changing the air boundary to a dielectric boundary reduces the effective electric length at the DGS aperture area. An equivalent circuit model is introduced to analyze the DGS transmission line and the resonator circuit designs. Due to the increase in the effective dielectric constant, the proposed structure can be realized with less sensitivity to metallic environments. From the experimental results, the proposed double-layered DGS can achieve a reduction of 90.1% in size and insensitivity at up to 5 mm of separation from the DGS aperture to the metallic plate.
关键词： equivalent circuit models,effective dielectric constants,radiation loss,size reduction,defected ground structures
更新于2025-09-23 15:23:52
-
Compact Dual-Channel Balanced Filter and Balun Filter Based on Quad-Mode Dielectric Resonator
摘要： In this paper, we propose a method for designing a dual-channel balanced filter and a dual-channel balun filter based on the quad-mode dielectric resonator (DR) for the first time. By sharing one common quad-mode DR, two balanced filters or two balun filters are integrated as one single-cavity configuration, featuring compact size and high integration. A cylindrical DR with two short ends is investigated to construct the quad-mode DR. By properly arranging input and output feeding probes, two modes of the DR are only excited by the feeding probes of one channel and the other two modes are excited by that of the other channel. Accordingly, signals cannot be transmitted between the two channels, resulting in high isolation. Moreover, the required out-of-phase characteristics of the balanced and balun filters can be obtained by the inherent electromagnetic field properties of the DR without adding additional circuits, featuring a simple structure. For demonstration, a dual-channel balanced filter and a dual-channel balun filter are designed and fabricated, showing excellent balanced or balun filter performance of each channel as well as high isolation between the two channels. As compared to the other reported DR balanced and balun filters, the proposed designs exhibit a significant size reduction, which are attractive in wireless systems.
关键词： Balanced filter,high Q factor,dielectric resonator (DR),balun filter,MIMO,size reduction,dual-channel
更新于2025-09-23 15:23:52
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Anomaly Preserving Content-Aware Hyperspectral Image Size Reduction
摘要： With the increase in the number and availability of imaging sensors, data size or dimensionality reduction, compression, archiving and retrieval algorithms are gaining importance. Whereas in the past, for hyperspectral images, the size reduction has been mostly concerned with the spectral domain, the increase in the number and spatial sizes of the hyperspectral images has raised the question whether a spatial reduction is also feasible. However, this reduction should be conducted in a content-aware fashion and should preserve the important and relevant information in the scene whether for archiving and retrieval purposes, or for following image processing tasks. In this work, an anomaly-preserving content-aware size reduction approach is proposed for hyperspectral images. The approaches utilizes seam carving with a spatial homogeneity energy function to preserve anomalies while performing reduction. Synthetic and real datasets are used to validate the proposed methodology.
关键词： size reduction,Anomaly,content-aware,hyperspectral,seam carving
更新于2025-09-23 15:21:21
-
Fluorescent Nanodiamonds || Producing Fluorescent Nanodiamonds
摘要： Natural diamonds in colors are commonly known as fancies, or fancy color diamonds, in gemstone industries. They are rare, beautiful, and some even carry impressive price tags in the jewelry market. By comparison, micro‐ and nanoscale diamond powders are low in price, with or without colors and fluorescent or not. These powders have been used as abrasives for grinding and polishing purposes since ancient time, mainly because of their extraordinary hardness. Little or no attention has been paid over the centuries to other properties of nanodiamonds such as their innate biocompatibility and light‐emitting capability. The invention of fluorescent nanodiamond (FND) in 2005 has revolutionized the field, opening a new area of research and development with diamonds. Experiments with FNDs in the last decade have demonstrated various promising applications of surface‐functionalized FNDs in diversified fields, ranging from physics and chemistry to biology and medicine. It is worthy of noting that as originated from the discovery of Radium by Marie Sk?odowska Curie (Section 3.2), FNDs may very well be called Madame Curie’s gemstones, valued appropriately as a scientist’s best friend.
关键词： fluorescent nanodiamonds,magnetically modulated fluorescence,fluorescence lifetime,size reduction,FND,ion irradiation,H3 centers,nitrogen-vacancy centers,electron irradiation,NV centers
更新于2025-09-23 15:21:01
-
[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Realization of Low-loss Epsilon-near-zero Properties Using PT-symmetric Metasurfaces
摘要： A circularly polarized patch antenna for future fifth-generation mobile phones is presented in this paper. Miniaturization and beamwidth enhancement of a patch antenna are the two main areas to be discussed. By folding the edge of the radiating patch with loading slots, the size of the patch antenna is 44.8% smaller than a conventional half wavelength patch, which allows it to be accommodated inside handsets easily. Wide beamwidth is obtained by surrounding the patch with a dielectric substrate and supporting the antenna by a metallic block. A measured half power beamwidth of 124? is achieved. The impedance bandwidth of the antenna is over 10%, and the 3-dB axial ratio bandwidth is 3.05%. The proposed antenna covers a wide elevation angle and complete azimuth range. A parametric study of the effect of the metallic block and the surrounding dielectric substrate on the gain at a low elevation angle and the axial ratio of the proposed antenna are presented.
关键词： microstrip patch antennas,Antenna radiation patterns,satellite antennas,size reduction,beamwidth enhancement
更新于2025-09-19 17:13:59
-
[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu, China (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Planar Printed Quasi-Yagi Antenna Designs Using Characteristic Modes
摘要： Characteristic mode (CM) analysis is conducted in this paper to understand the physical aspects of a compact planar quasi-Yagi antenna at the lowest resonant frequency for achieving bandwidth enhancement and electrical size reduction. The quasi-Yagi antenna comprises a microstrip feeding line, a driver dipole and two parasitic strips. The driver dipole is modified by symmetrically adding two capacitive coupling structures, which are connected with the ground plane in the other end, through examining the behavior of the CMs. A capacitor with proper value is adopted in the feeding line for better impedance matching in the higher band. Through the work in this paper, the lowest frequency with VSWR < 2 is extended to 3.09 GHz from 3.65 GHz with no physical size enlarged. Its bandwidth is enhanced with a ratio of about 3.78 : 1.
关键词： bandwidth enhancement,characteristic modes,Quasi-Yagi antenna,size reduction
更新于2025-09-10 09:29:36
-
[IEEE 2018 International Power Electronics Conference (IPEC-Niigata 2018 –ECCE Asia) - Niigata, Japan (2018.5.20-2018.5.24)] 2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia) - Optimized Selection and Utilization of DC-Link Capacitor in a Single-Phase PV Grid Inverter System
摘要： Single-phase PV grid inverters usually require large reservoir capacitors on the DC-Link to absorb 2nd order harmonics. This paper shows in a design how to improve the utilization of metalized polypropylene film capacitor (MPFC) specifications in multiple dimensions simultaneously: break-down voltage rating, capacitance, ripple current capability and warranted reliability performance. As a result, the system size and cost can be reduced, while the overall energy capturing efficiency is guaranteed. Under low-capacitance conditions the DC-Link voltage varies within a fundamental cycle; a boost converter is placed between the PV panel and the DC-Link to provide MPPT (maximum power point tracking). The modulation index of the output inverter can be dynamically varied for waveform compensation. Comparison is made with electrolytic capacitors and it is found that when using an optimized capacitor selection strategy, it is possible to mitigate the increased size and cost implications of film capacitors. Simulation demonstrates the design of a 2.5kW system, while experiment is conducted to prove the design concept.
关键词： size reduction,metalized polypropylene film capacitor,reliability,cost,PV inverter
更新于2025-09-09 09:28:46