- 标题
- 摘要
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- 实验方案
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Space-Frequency Joint Contention Scheduling Algorithm based on AoD in SDM-EONs
摘要： Compared with elastic optical networks, spectrum contention problem may become more serious in space-division multiplexing elastic optical networks. Spectrum converters (SCs) can effectively resolve the problem of spectrum contention without additional delays, but SCs have the disadvantages of complicated technologies and high costs. To resolve the two problems aforesaid, taking into account the alleviated spectrum continuity constraint caused by the space dimension and the node flexibility introduced by architecture on demand (AoD), a space-frequency joint contention scheduling algorithm (SFJSA) based on AoD is proposed in this paper. SFJSA divides the contention scheduling process into two phases: scheduling in space domain and in frequency domain. It gives priority to resolve contention in the spatial domain, and then considers using spectrum converters in spectrum domain. In the stage of space switching, a weight formula is designed to balance the costs of spectrum selective switches and the loads of cores. In the stage of spectrum conversion, a concept of spectrum compactness is introduced to further optimize the utilization of spectrum resources and spectrum converters. The simulation results indicate that the proposed algorithm can reduce the number of spectrum converters required while improving the blocking performance, which means it achieves better blocking performance in a more cost-effective manner.
关键词： Space division multiplexing elastic optical networks,Bandwidth blocking probability,Architecture on demand,Spectrum converter,Space-Frequency Joint Scheduling
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE Photonics Conference (IPC) - Reston, VA, USA (2018.9.30-2018.10.4)] 2018 IEEE Photonics Conference (IPC) - THz Photonic Transmitters with Type-II Hybrid Absorber UTC-PDs and Dual-Ridged Horn Antennas for High-Power and Extremely wide Fractional Bandwidth Performances
摘要： Waveguide-coupled THz photonic transmitters, which have novel design of dual-ridged horn antenna and ultra-fast photodiodes, demonstrate extremely wide 3-dB fractional O-E bandwidth (100%; 0.1-0.3 THz). A reasonable power (31.6 μW; 0.24 THz) can be detected in the receiving-end through wireless transmission.
关键词： Extremely wide fractional bandwidth,High-power,THz photonic transmitters,Dual-ridged horn antennas,Type-II hybrid absorber UTC-PDs
更新于2025-09-09 09:28:46
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CPW-FED CIRCULARLY POLARIZED SQUARE SLOT ANTENNA WITH ENHANCED BANDWIDTH AND REDUCED SIZE FOR WIDEBAND WIRELESS APPLICATIONS
摘要： A coplanar waveguide-fed circularly polarized square slot antenna with the feasibility of obtaining a wider bandwidth and a relatively smaller size is proposed and demonstrated. The proposed antenna, consisting of a stepped feeding strip, a modified grounded L-shaped radiating patch, an inverted-L grounded strip and an asymmetric ground with an L-shaped slot as well as two horizontal slots, is designed, analyzed and fabricated. Good agreement between simulated and measured results is observed. Simulation and measurement results reveal that the proposed antenna can provide an impedance bandwidth of 106.3% (2.3–7.52 GHz) and a 3-dB axial ratio (AR) bandwidth of 90.2% (2.25–5.95 GHz). Additionally, within the effective circular polarization (CP) bandwidth of 88.5% (2.3–5.95 GHz), the proposed antenna has gains from 1.9 dBic to 5.2 dBic with an average gain of 3.9 dBic.
关键词： Coplanar waveguide-fed,wideband wireless applications,reduced size,square slot antenna,enhanced bandwidth,circularly polarized
更新于2025-09-09 09:28:46
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High performance InGaN double channel high electron mobility transistors with strong coupling effect between the channels
摘要： In this paper, high performance InGaN double channel (DC) high electron mobility transistors (HEMTs) are proposed and systematically investigated. Due to the coordination of double InGaN channels, a large maximum drain current density and a distinct double-hump feature of the transconductance and frequency performance are achieved. More importantly, it is revealed that the coupling effect between the two InGaN channels is much stronger than that of the conventional GaN DC HEMTs. This characteristic leads to a remarkable enhancement in the gate voltage swing, indicating the excellent linearity of the InGaN DC HEMTs at both dc and rf conditions. Benefiting from the enhanced electron confinement in InGaN channels, the fabricated HEMTs show a low off state drain leakage current of 0.26 μA/mm and a high on/off current ratio (Ion/Ioff) of 5.1 × 106. In addition, the desirable current collapse and breakdown characteristics are also obtained. This work convincingly demonstrates the great potential and practicality of the InGaN DC HEMTs for high power and high bandwidth applications.
关键词： high power,InGaN,double channel,high electron mobility transistors,high bandwidth,coupling effect,linearity
更新于2025-09-09 09:28:46
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Broadband and high uniformity Y junction optical beam splitter with multimode tapered branch
摘要： A high uniformity and broad bandwidth Y junction optical beam splitter is proposed and analyzed in this paper based on silicon-on-insulator platform. By replacing the uniform branch with the multimode tapered branch, the bandwidth and the power uniformity of two output ports are improved prominently. Furthermore, the sensitivity to fabrication accuracy is reduced by widening the splitting angle. The simulation and the experimental results confirm that the bandwidth is larger than 100nm, the power uniformity of two output ports is enhanced 4 dB, whereas the insertion loss is less than 0.6dB and the return loss is larger than 26dB, respectively.
关键词： Multimode,Beam splitter,Broad bandwidth,High uniformity,Tapered branch
更新于2025-09-04 15:30:14
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The study of quantum efficiency in PIN photodiodes in terms of temperature and capacitive effects under non-uniform illumination conditions
摘要： In this article the impacts of quantum efficiency and bandwidth of PIN photodiodes under non-uniform illumination conditions are investigated. An absorption region is divided into the number of arbitrary layers and the continuity equations for each layer are solved with assuming that the carrier’s drift velocity is constant in each layer. Also the impact of transit time and capacitive effects of bandwidth were studied with considering the bias voltage, width of absorption region and temperature. The results show that with considering the capacitive effects, the bandwidth is increased by increase in temperature and bias voltage. We observe the effect of incident optical radiation from two n and p sides and also its impact on bandwidth and quantum efficiency. The results show more impact of radiation from n region compared to p region.
关键词： Temperature,Capacitive effect,PIN photodiode,Quantum efficiency,Bandwidth
更新于2025-09-04 15:30:14
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A MINIATURIZED TUNABLE BANDPASS FILTER WITH CONSTANT FRACTIONAL BANDWIDTH
摘要： This paper presents a miniaturized tunable bandpass ?lter, consisting of two coaxial dielectric resonators and a pair of parallel-coupled lines. A coaxial dielectric resonators and a microstrip line form a new step-impedance resonator (SIR), which is di?erent from a conventional SIR. Varactor diodes are connected to SIRs to tune the center frequency. The gap between parallel-coupled lines controls the inter-stage coupling coe?cient. Lumped inductors used for coupling to I/O ports can reduce design complexity. The variations of coupling coe?cient and external quality factor with tuning frequency are analyzed using HFSS software. A appropriate coupling coe?cient which satis?es with constant fractional bandwidth within the tuning range is available. A tunable ?lter has been made of dielectric ceramics with dielectric constant of 38, fabricated on dielectric substrate and measured using Networks analyzer. Center frequencies vary from 0.43 GHz to 0.78 GHz, 3 dB fractional bandwidth from 6.4% to 6.8% when bias voltages are applied from 0 V to 10 V. The measured results validate the approach and agree with the simulation.
关键词： varactor diodes,constant fractional bandwidth,coaxial dielectric resonator,step-impedance resonator,tunable bandpass ?lter
更新于2025-09-04 15:30:14
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An Implantable Wideband Circularly Polarized Microstrip Patch Antenna via Two Pairs of Degenerate Modes
摘要： This paper presents a design approach to developing a wideband circularly polarized (CP) microstrip patch antenna (MPA) embedded in the human body. To achieve this goal, a pair of high-order degenerate modes (TM30 and TM03) in MPA have been excited and lowered for resonance in proximity to a pair of fundamental degenerate modes (TM10 and TM01). The proper disturbance of these two pairs of radiative resonant modes can contribute to the generation of two CP radiating waves at two near-by operating frequencies, aiming to realize CP radiation in a wide operating band covered by these two frequencies. A novel implantable wideband CP MPA is proposed and developed due to the emergence of two minima in the axial-ratio (AR) frequency response. The designed MPA is then demonstrated to tremendously achieve the wide 3-dB AR bandwidth which covers the 2.4 to 2.48 GHz ISM-band in the cubic human skin model. Moreover, the proposed CP MPA shows good tolerance to the variety of tissue according to our study on sensitivity and model integrity. Finally, the designed CP MPA is fabricated and tested, and a good agreement exists between measured and simulated results in a wide frequency region.
关键词： Implantable Antenna,Lower and Upper Degenerate Modes,Wide Bandwidth,Circular Polarization
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland, New Zealand (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Wideband Metamaterial Antenna Design
摘要： This paper presents the design of composite right/left handed (CRLH TL) wideband metamaterial antenna. The bandwidth enhancement was achieved by replacing horizontal ohm’s shape slot with series horizontal slot. A comprehensive parametric analysis using Computer Simulation Technology CST software is carried out by varying the position of the slot Ln to determine the effectiveness of the concept and find the right position of the slot for obtaining the wideband. From the simulation work, it was found that the impedance bandwidth covered from 2.2 GHz to 4.6 GHz which is equivalent to 75% fractional bandwidth. The antenna has a compact size of 30 by 16.80 mm2. It has three different resonating bands at 2.6 GHz, 3.4 GHz and 4.5 GHz within the range with realised peak gain of 2.39 dBi, 2.41 dBi, and 3.22 dBi respectively and average efficiency of 95%.
关键词： wideband,metamaterial,composite right hand left hand transmission line,computer simulation technology (CST),bandwidth
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland, New Zealand (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Broadening the Bandwidth of the Electromagnetic Metamaterial Absorber
摘要： In this paper, we will first review the application of metamaterial concept to design electromagnetic wave absorber and discuss its limitation on absorption bandwidth. Then we will show several approaches to expand the working bandwidth of metamaterial absorber including the employment of multi-resonator meta-atoms, adjusting the loss in the meta-atom resonance, as well as utilizing metasurface in the Salisbury screen design. Various design examples will be discussed that verified the feasibility of these approaches.
关键词： metasurface,metamaterial,broad bandwidth,absorber
更新于2025-09-04 15:30:14