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A novel compact wideband filter using three-mode dual-ring resonator
摘要： A novel compact wideband filter using three-mode dual-ring resonator is presented in this article. The resonator is constructed by two quarter wavelength transmission lines and a cascaded half wavelength dual-ring. Formulae based on even- and odd-mode analysis are derived to analyze the locations of the transmission poles and zeros of the resonator. Due to the transmission zeros in the lower and upper stopbands, the proposed filter exhibits sharp attenuations near the passband as well as very wide stopband. The filter is successfully realized by full wave EM simulation and fabricated. The measured responses of the filter agree well with the design simulation, and show that the fabricated filter has an insertion loss of better than 1.5 dB in the passband and two rejections of greater than 20 dB in the stopbands from 0 to 10GHz.
关键词： even- and odd-mode analysis,dual-ring resonator,wideband filter,transmission zeros,three-mode
更新于2025-09-10 09:29:36
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Scatterer Surface Design for Wave Scattering Application
摘要： In this paper, radio wave scattering is considered and an optimal scatterer surface is realized. For this purpose, an ultra-wideband and high-efficiency polarization converter unit-cell is proposed. Here, the proposed polarization converter unit-cell and its mirror are combined to provide 180? phase difference for scattering purposes. The desired combination of unit-cells which produces uniform scattering pattern and maximum wave attenuation achieved employing group search optimization (GSO) algorithm. For the problem at hand, the GSO optimization algorithm is presented in bi-level format including master and slave levels. Simulation and experimental results showed that the 10 dB bandwidth of normalized RCS reduction is achieved in ultra-wideband ranging from 5.5 GHz to 20.51 GHz with a fractional bandwidth of 115%, assuring a favorable performance of the proposed method. In addition, a wide angle bistatic RCS reduction over a wide frequency band is attained.
关键词： scatterer structure,ultra-wideband,radio-wave scattering,Polarization rotation (PR)
更新于2025-09-10 09:29:36
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All-optical notch filters for ultra-wideband chaotic communications
摘要： In this paper, a wideband all-optical notch ?lter is proposed using two cascaded modi?ed add-drop resonators from chalcogenide glass (ChG) and GaAsInP-InP waveguide materials. The system consists of ChG main ring and two small side rings called phase modulators made of the GaAsInP-InP materials. The plane waves are fed at the input and add ports, from which the chaotic signal outputs can be generated by the nonlinear e?ect induced into the center ring. The results have been simulated based on the scattering matrix method. Results have shown that the generated chaotic signals can be used for switching and secured communications. An ultra-fast switching time of ～ 2 attoseconds is achieved. Moreover, the chaotic signals can be ?ltered by the stop band ?lters (notch ?lters). The free spectral range (FSR) of two cascaded ChGs is 1494.8 nm. The output wavelength of the notch ?lters is tunable from 748.0–2242.2 nm and 2242.8–3737.0 nm. The band-stop of the notch ?lter is 1494.2 nm. This approach will allow the implementation of the compact, and integrated notch ?lters in an on-chip scale circuit, which is useful for both light ?delity (LiFi) and wireless ?delity (WiFi) applications.
关键词： WiFi,all-optical notch ?lters,chalcogenide glass,GaAsInP-InP,scattering matrix method,ultra-wideband chaotic communications,LiFi
更新于2025-09-10 09:29:36
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Beyond the Bode-Fano Bound: Wideband Impedance Matching for Short Pulses Using Temporal Switching of Transmission-Line Parameters
摘要： Impedance matching is one of the most important practices in wave engineering as it enables one to maximize the power transfer from the signal source to the load in the wave system. Unfortunately, it is bounded by the Bode-Fano criterion which states that, for any passive, linear, and time-invariant matching network, there is a stringent trade-off between the matching bandwidth and efficiency, implying severe constraints on various electromagnetic and acoustic wave systems. Here, we propose a matching paradigm that overcomes this issue by using a temporal switching of the parameters of a metamaterial-based transmission line, thus revoking the time-invariance assumption underlying the Bode-Fano criterion. Using this scheme we show theoretically that an efficient wideband matching, beyond the Bode-Fano bound, can be achieved for short-time pulses in challenging cases of very high contrast between the load and the generator impedances, and with significant load dispersion, situations common in, e.g., small antenna matching, cloaking, and with applications for ultrawideband communication, high resolution imaging, and more.
关键词： Bode-Fano criterion,wideband matching,metamaterial,transmission line,Impedance matching
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) - A Vertically-Polarized Ultra-Wideband, Low-Profile and Folded Half Vivaldi Antenna
摘要： A vertically-polarized, ultra-wideband (UWB), low-profile Vivaldi antenna is presented in this paper. Only half of the Vivaldi is placed perpendicularly to the ground plane to achieve vertical polarization. The upper part of the antenna is folded into a right angle to achieve a low-profile. The rectangular slotlines are used to improve VSWR and enhance the gain at the end-fire orientation in the operating frequency band, and a 50? coaxial probe connects directly with the end of taper slot for feeding purpose. The total sizes are 100 (length) × 50 (width) × 16 (height) mm3. Simulated results show that the designed antenna exhibits a bandwidth from 3.2 to 24 GHz (7.5:1) for VSWR<2.2, and stable radiation patterns in 3 ~ 16 GHz.
关键词： vivaldi antenna,ultra-wideband,vertical polarization,rectangular slotline
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) - Conducted EMI Causing Error Readings of Static Electricity Meters
摘要： Following initial studies showing that conducted electromagnetic interference (EMI) can lead to large error readings of static electricity meters, VSL performed a thorough verification study confirming that wideband currents produced by non-linear, fast-switching loads indeed can lead to significant error readings of static meters. Key parameters of the EMI causing the errors are a short rise time and large peak height of the current step. When dimming linear or non-linear loads such as heaters and energy-saving lamps, the (lack of) internal filter in the dimmer has a large influence on these key parameters.
关键词： Electromagnetic compatibility,energy measurement,wideband current,watthour meters,static meter,revenue metering,smart meter,standards,interference,EMI
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) - A Wideband Magnetometer Implemented by the Optically Induced Fictitious Magnetic Field Technology
摘要： We propose a wideband magnetometer based on the classical Mx method realized with the multiple ?ctitious magnetic ?elds by applying a spatial light modulator and a microlens array. We give a brief theoretical description of the optically induced ?ctitious magnetic ?eld and introduce the experimental setup of this magnetometer. Compared with the traditional magnetometers, the band of this magnetometer is user-de?ned and can cover up MHz order of magnitude, which is conducive to measure the interference magnetic ?eld with wide frequency band.
关键词： wideband magnetometer,magnetometer,optically induced ?ctitious magnetic ?eld,high-precision,interference magnetic ?eld
更新于2025-09-10 09:29:36
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Wideband balun filter on slot-line resonator with intrinsic balanced performance in magnitude and phase
摘要： In this article, a novel wideband balun filter on the coupled slotline-line resonator topology with intrinsic balanced performance in magnitude and phase performance is presented. The proposed wideband balun filter consists of four uniform half-wavelength slot-line resonators (SLRs) in middle, one single-ended unbalanced port, and one balanced port with two terminals. By utilizing the distinct field conversion from the slotline to the microstrip line feeding line, the proposed technique can realize good balanced performance inherently in magnitude and phase over a wideband frequency range. In order to demonstrate the proposed scheme and support the design conception, one circuit prototype is designed, fabricated, and tested. All of the measured results of the frequency response, magnitude, and phase imbalance performance agree well with the simulated one, and these results have effectively demonstrated its good filtering property, intrinsic balanced performance in magnitude and phase over a wide band frequency.
关键词： slotline resonator (SLR),phase imbalance,magnitude imbalanced,balun filter,balanced performance,wideband
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) - Calibration of Current Shunt Standards in the Megahertz Region
摘要： Beyond 1 A (from 2 A to 100 A typically) standard current shunts are currently calibrated in magnitude up to 100 kHz and in phase angle up to 200 kHz. For such high current levels and above these frequencies the existing traceable measurement methods are not able to characterize current shunts and cannot provide the phase and magnitude of impedance simultaneously. This paper briefly describes a new broadband method for measuring current shunt standards beyond 1 A in the megahertz region and presents experimental results demonstrating the efficiency of this approach.
关键词： Calibration method,current measurement,VNA,uncertainty,current shunt,phase angle,wideband measurements,ac-dc difference
更新于2025-09-10 09:29:36
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UWB Dual-polarized Dipole Array with Dielectric and FSS Superstrate and 65o Scanning
摘要： We report the design of an ultra‐wideband, dual‐polarized, tightly coupled dipole array (TCDA) with an integrated balun for wide angle scanning. A dual‐pol dipole design enables massive bandwidth, large scanning volume, and high polarization purity, concurrently. To achieve wide angle impedance matching without exciting surface waves, two types of superstrates are evaluated on a finite array: 1) dielectric superstrate and 2) novel planar frequency selective surface (FSS). The latter architecture is capable of scanning 70° in E Plane and 65° in H Plane and shows, on average, 5° scanning improvement to the former. The impedance bandwidth is 5.25:1 (0.8‐4.2 GHz) at the broadside (VSWR<2). The bandwidth reduces to 4.3:1 (0.9‐3.9 GHz) when maximum scanning angle or θmax increases to 65° for the H plane and 70° for the E plane (VSWR < 3.2). The proposed array is a great candidate for wide‐angle wide‐band scanning applications covering the entire L and S bands.
关键词： dielectric superstrate,FSS,wide angle scanning,TCDA,Ultra-wideband,frequency selective surface,dual-polarized,tightly coupled dipole array,integrated balun
更新于2025-09-10 09:29:36