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- 实验方案
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Quasi-Elliptic Waveguide Dual-Band Bandpass Filters
摘要： This article presents a novel folded configuration of dual-band filter employing TE11m dual-mode elliptical cavity resonators. The proposed side-coupled configuration leads to a significant reduction of filter footprint compared with previously reported in-line dual-band filter structures. Such configuration also facilitates cross couplings to realize advanced quasi-elliptic filter functions. The structure employs irises for both sequential and cross couplings. The limitations of bandwidth realization and spurious-free window are analyzed in detail, and new coupling structures are proposed to improve the overall in-band and out-of-band responses. All the proposed dual-band designs have low insertion loss and allow for independent control of each frequency and coupling parameter. To demonstrate the concept, two 8-pole C-band elliptical cavity dual-band filters are designed, manufactured, measured, and compared. To the best of the authors’ knowledge, this is the first reported folded dual-band filter configuration based on metallic waveguide cavities.
关键词： elliptical cavity,transmission zeros (TZs),waveguide,dual-band filter,dual-mode resonator,folded structure,Bandwidth
更新于2025-09-11 14:15:04
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A Novel Temperature Controlled Broadband Metamaterial Absorber for THz Applications
摘要： A broadband switchable metamaterial absorber is investigated in this paper. The switchable response is achieved by utilizing the phase transition property of vanadium dioxide (VO2) that is thermally controlled. A novel band extension scheme is presented by introducing capacitive coupling effects among the resonators. By exploiting the coupling effect, near octave bandwidth is achieved when referred to an absorptivity of 90%. Further, by integrating the temperature controlled VO2 film into the dielectric layer, the proposed absorber can be switched between a frequency band from 0.32 THz to 0.56 THz and another band from 0.356 THz to 0.682 THz that is achieved by changing the operation temperature. Due to the symmetrical structure, the studied absorber features polarization insensitive and a wide incident angle of up to 50?. The broadband and switchable properties are discussed based on the resonant structure, surface current distributions, electric field distributions and impedance matching. It is noted the presented method can be scaled to other adjacent THz frequency band.
关键词： phase change material,metamaterial absorber,Broadband,switchable bandwidth
更新于2025-09-11 14:15:04
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[ASME ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems - San Antonio, Texas, USA (Monday 10 September 2018)] Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies - Experimental Studies on a Compressive-Mode Piezoelectric Transducer for Low-Frequency and Wide-Band Energy Harvesting
摘要： In this paper, we report a low-frequency and wide-bandwidth piezoelectric energy transducer. The transducer is designed based on a piezoelectric plate, a truss mechanism, a spring-mass system and a stopper. The spring-mass system receives kinetic energy from excitation and induces forces, which are transmitted, amplified by truss mechanism and applied onto the piezoelectric plate. The stopper is added to truncate the amplitude of the mass. The mass and the stopper interact through impacts. The impact force triggers dynamic bifurcation in the transducer. By taking advantage of the superharmonic resonances and nonlinearity born from the bifurcation, the transducer is able to work efficiently with a wide bandwidth. Through experiment studies on a fabricated prototype, the lowest resonant frequency is around 3.2Hz with the peak-peak voltage output up to 55V. The bandwidth of the transducer is approximately 4.5Hz out of our targeted frequency domain [2.5Hz, 10Hz], broadened by up to 20 times compared to that of the linear system without the stopper.
关键词： superharmonic resonances,wide-bandwidth,low-frequency,piezoelectric energy transducer,nonlinearity
更新于2025-09-10 09:29:36
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Processing and Bandwidth Resource Allocation in Multi-Provider NFV Cloud Infrastructures interconnected by Elastic Optical Networks
摘要： The paper proposes and investigates solutions to the computing and bandwidth resource allocation problem in Multi-Provider Network Function Virtualization (NFV) environment. The scenario is characterized by Cloud Infrastructures (CI) managed by different providers and interconnected by an Elastic Optical Networks (EON). The objective is to allocate resources for a given number of Service Function Chains (SFC) known in advance so as to minimize the sum of the processing and bandwidth costs and to take into account both the different processing costs charged by the Cloud Infrastructure (CI) providers and the sub-carrier consecutiveness, spectrum continuity and spectrum clash constraints. In particular we evaluate the operational cost saving that the proposed solutions allow us to obtain with respect to the case in which traditional resource allocation algorithms are applied.
关键词： Computing Resources,Bandwidth Resources,Elastic Optical Networks,Network Function Virtualization
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE Symposium on Computers and Communications (ISCC) - Natal, Brazil (2018.6.25-2018.6.28)] 2018 IEEE Symposium on Computers and Communications (ISCC) - Dynamic Bandwidth Allocation with Multi-ONU Customer Support for Ethernet Passive Optical Networks
摘要： This paper introduces a mechanism for the support of multi-ONU service level agreements (SLAs) in dynamic bandwidth allocation (DBA) algorithms for Ethernet passive optical networks (EPON). The employment of SLAs for multiple optical network units (ONUs) instead of individual ONUs allows better utilization of the bandwidth reserved for these ONUs. The proposed DBA mechanism allows customers owning multiple ONUs to redistribute the aggregated bandwidth of the group of ONUs to better balance the bandwidth utilization. The proposed DBA can be employed in different use cases such as mobile backhauling/fronthauling, PON virtualization, and multi-site enterprise networking. Simulation results show that the proposed DBA improves the network performance.
关键词： Dynamic Bandwidth Allocation,Mobile Backhauling/Fronthauling,Quality of Service,Network Virtualization,Passive Optical Networks
更新于2025-09-10 09:29:36
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Performance Analysis and Constellation Optimization of Star-QAM-Aided Differential Faster-than-Nyquist Signaling
摘要： In this letter, motivated by the recent differential faster-than-Nyquist (DFTN) signaling concept, we propose an improved 16-point double-ring star quadrature amplitude modulation (QAM)-aided DFTN signaling transmission, which allows us to attain a higher bandwidth ef?ciency as well as a simple receiver based on noncoherent detection. We derive an analytical error-rate bound for the proposed star-QAM DFTN signaling in an uncoded scenario. The derived bound is used for optimizing the star-QAM constellation for our DFTN signaling in terms of error-rate performance in an uncoded scenario. Our simulation results demonstrate that the proposed star-QAM DFTN scheme outperforms its conventional phase-shift-keying-based DFTN counterpart.
关键词： noncoherent detection,bandwidth efficiency,Differential faster-than-Nyquist (DFTN) signaling,star quadrature amplitude modulation (QAM),error-rate performance
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Effect of Input Bandwidth of a Sampler on Differential Sampling Based on a Programmable Josephson Voltage Standard
摘要： We have investigated the response characteristics of two different samplers, Keysight 3458A and NI 5922 implemented in setup for differential sampling based on a programmable Josephson voltage standard, to input signals in a frequency range below 1 kHz. The RMS amplitudes measured with the samplers coincides within a few parts in 106 at frequencies below 100 Hz. However, the difference between the RMS values increases with the frequency, mainly due to the dramatic change of the value obtained with the Keysight 3458A. The difference reaches up to 25 μV/V at 1 kHz. The feature is inferred to originate from the difference in the input bandwidths for the two samplers.
关键词： input bandwidth of sampler,RMS value,programmable Josephson voltage standard,differential sampling
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Time Latency of DC Input Path for 3458A Sampling Multimeter
摘要： The Keysight 3458A is a common digitizer because of the great accuracy and small integration time. The bandwidth of its DC input path varies depending on the magnification of input amplifier of different ranges, which causes time latency of input signal. A method to measure the latency based on aperture time is introduced. When the aperture approximately equals to the period of the signal under test, extremum of sampling value reflects signal's initial phase. Experiments at 1V and 10V ranges with input signals of 25kHz and 50kHz were carried out and the time latency were measured. Then the bandwidth were calculated which were the same of about 120kHz for these two ranges.
关键词： phase shift,time latency,synchronous sampling,bandwidth,Aperture time
更新于2025-09-10 09:29:36
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Improved design of CELC meta-resonators for bandwidth improvement and miniaturization of patch antenna
摘要： 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.
关键词： ELC resonator,bandwidth improvement,patch antenna,metamaterial resonators,miniaturization
更新于2025-09-10 09:29:36
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[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