- 标题
- 摘要
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- 实验方案
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Compact Wideband Hybrid Filters in Rectangular Waveguide With Enhanced Out-of-Band Response
摘要： This article describes the design procedure of a compact wideband waveguide filter, based on stepped impedance resonators (SIRs) and a combined usage of capacitive and inductive coupling irises, that provides a significant improvement in the out-of-band response of the filter with respect to the state-of-the-art. In addition to theory, several filter prototypes have been designed and manufactured. A detailed sensitivity analysis has also been carried out. Finally, simulations and measurements are compared, showing very good agreement, thereby fully validating the new filter topology.
关键词： Aggressive space mapping (ASM),stepped-impedance resonator (SIR),bandpass filters,wideband,hybrid (inductive and capacitive) irises
更新于2025-09-12 10:27:22
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[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - Wideband slow light in grating waveguides
摘要： In this work, a wide band slow light is achieved in a simple one-dimensional grating waveguide. A flat band indicating slow light with group index of 13 and bandwidth over 10nm is obtained.
关键词： grating waveguide,wideband,slow light
更新于2025-09-12 10:27:22
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Wideband Omnidirectional Slotted-Waveguide Antenna Array Based on Trapezoidal Slots
摘要： This manuscript presents a novel approach for designing wideband omnidirectional slotted-waveguide antenna arrays, which is based on trapezoidal-shaped slots with two different electrical lengths, as well as a twisted distribution of slot groups along the array longitudinal axis. The trapezoidal section is formed by gradually increasing the slot length between the waveguide interior and exterior surfaces. In this way, a smoother impedance transition between waveguide and air is provided in order to enhance the array operating bandwidth. In addition, we propose a twisting technique, responsible to improve the omnidirectional pattern, by means of reducing the gain ripple in the azimuth plane. Experimental results demonstrate 1.09 GHz bandwidth centered at 24 GHz (4.54% fractional bandwidth), gain up to 14.71 dBi over the operating bandwidth, and only 2.7 dB gain variation in the azimuth plane. The proposed antenna array and its enabling techniques present themselves as promising solutions for mm-wave application, including 5G enhanced mobile broadband (eMBB) communications.
关键词： 5G,trapezoidal slots,wideband,omnidirectional,mm-wave,slotted-waveguide antenna array
更新于2025-09-12 10:27:22
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Magneto-Optical Isolator Based on Ultra-Wideband Photonic Crystals Waveguide for 5G Communication System
摘要： This paper presents a novel magneto-optical isolator based on an ultra-wideband and high efficiency photonic crystals (PCs) waveguide and gyromagnetic ferrites. The three-dimensional numerical simulation finds that the photonic crystals waveguide’s (PCW) transmission efficiency rises with its height and width. The corresponding experiments are performed by using a triangular lattice Al2O3 dielectric posts array in 5G millimeter wave band. The measured transmission efficiency is up to 90.78% for the optimal PCs waveguide structure, which has ultra-wide operating bandwidth from 23.45 to 31.25 GHz. The magneto-optical isolator is designed by inserting two rectangular gyromagnetic ferrites into the PCs waveguide. Due to the contrast between the effective permeability of the left and right circular polarization waves passing through the magnetized ferrite sheets, the ferromagnetic resonance absorption of the forward and reverse waves is different. By using finite element method, the isolation is optimized to be 49.49 dB for the isolator and its relative bandwidth reaches 8.85%. The high isolation, broadband, and easy integration indicate that our designed magneto-optical isolator has significant advantage in 5G communication systems.
关键词： photonic crystals waveguides,magneto-photonic isolator,wideband,5G communication,photonic band gap
更新于2025-09-12 10:27:22
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A 230-GHz High-Power and Wideband Coupled Standing Wave VCO in 65-nm CMOS
摘要： This article presents a 230-GHz wideband harmonic voltage-controlled oscillator (VCO) with large output power based on a compact and low-loss structure of coupled standing wave oscillators. In order to boost the output power, oscillators are coupled together without adding extra passive loss to the circuit. Transistors with inductive drain impedances provide the necessary negative resistance to the oscillators while simultaneously acting as active variable capacitors for frequency tuning and generate the desired second-harmonic power through their nonlinearities. Transmission lines at the drains are responsible for creating the inductive impedance as well as coupling adjacent oscillators and routing and combining the output power. Therefore, the circuit has a compact structure that minimizes passive losses. A varactor-less frequency tuning scheme is used and allows for wideband operation without sacrificing the output power. In addition to oscillator coupling and minimizing the losses, the output power has been boosted by engineering the harmonic impedance that is seen by the transistors in the circuit. The prototype chip was implemented in a 65-nm CMOS process. The output power of the VCO covers 219–238 GHz frequency band (8.35% tuning range) and delivers 3.4-dBm maximum output power. The minimum measured phase noise is ?105.8 dBc/Hz (at 10-MHz offset) while consuming 195 mW from a 1.5-V supply.
关键词： standing wave,low-loss,THz,wideband,frequency tuning,Compact structure,millimeter-wave (mm-Wave),voltage-controlled oscillator (VCO),mm-wave/terahertz (THz) power generation,harmonic oscillator,varactor-less
更新于2025-09-12 10:27:22
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Development of a Wide Band TEM-based Bethe Hole Coupler Using Ridge Gap Waveguide Technology
摘要： A 20 dB Bethe Hole coupler is designed and fabricated using ridge gap waveguide technology for operation at the Ku band. The use of ridge gap waveguide concept makes an opportunity to develop a lowloss and wideband directional coupler because of supporting TEM wave propagation in air region.The simulation results show a very flat -20dB coupling coefficient response, higher than 20dB isolationand proper impedance matching over a wide frequency rangewhich are in agreement with the measurement results.
关键词： TEM,Bethe hole,Coaxial probe,Wideband,Ridge gap waveguide
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Cherenkov Generation of Wideband Terahertz Radiation using a Sub-Micron LiNbO <sub/>3</sub> Slab Waveguide
摘要： Terahertz (THz) radiation is critical to the areas of security, medicine, communications, and consumer applications. THz generation is often achieved using lithium niobate, LiNbO3, since it has a high nonlinear coefficient in this regime (d33=180 pm/V [1]). Dramatic improvement to the generation efficiency has been achieved by incorporating this material into waveguiding configurations [2,3], since waveguides allow the pump pulse to remain confined over large distance (millimeters or longer). To date, waveguides investigated for THz generation utilize transverse core dimensions larger than a few microns. However, when the waveguide core is sub-wavelength with respect to the pump wavelengths, as well as the generated THz wavelengths, another benefit is observed: substantial broadening of the generated THz bandwidth. Here, we report on a sub-wavelength SiO2-LiNbO3-SiO2 slab waveguide that produces wideband THz radiation and emits it in the form of Cherenkov waves. The investigated LiNbO3 slab waveguide has transverse core dimensions of 720 nm × 4 mm and a length of 100 μm. This waveguide is excited using an electric field pulse having a duration of 50 fs and a central-wavelength of 780 nm. Figure 1(a) shows the generated THz electric field pulse, which has the short duration of <1 ps. The power spectrum of the generated THz pulse is shown in Fig. 1(b), having a central-frequency of 6.9 THz and a full-width half-maximum (FWHM) bandwidth of 2.1 THz. Notably, LiNbO3 has a strong phonon resonance at 7.6 THz [4]. However, since the generated THz radiation is emitted as Cherenkov waves, it exits the sub-wavelength LiNbO3 core after propagating a distance much less than a wavelength. This characteristic minimizes the high loss of the LiNbO3 phonon resonance, allowing for generation to occur directly at this phonon resonance. As such, the sub-wavelength nature of the LiNbO3 core allows for dramatic improvement to the THz radiation bandwidth. The data is Fig. 1 is obtained by performing finite-difference time-domain simulations. Experimental verification of this result is currently underway. In this experimental work, the LiNbO3 slab waveguide instead has a length of 1 cm and the excitation pulses will have energies ranging up to 200 nJ.
关键词： wideband THz generation,Terahertz radiation,LiNbO3,Cherenkov waves,sub-wavelength waveguide
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE MTT-S International Wireless Symposium (IWS) - Guangzhou, China (2019.5.19-2019.5.22)] 2019 IEEE MTT-S International Wireless Symposium (IWS) - A Self-Packaged Ultra-Wide Band Bandpass Filter Using Integrated Substrate Gap Waveguide
摘要： An ultra-wideband bandpass (UWB) filter using integrated substrate gap waveguide (ISGW) technology is proposed, which has ultra-wideband and high selectivity. The UWB ISGW bandpass filter structure consists of three layer dielectric substrates, the top substrate uses metallic via-holes and metallic patches to implement perfect magnetic conductor (PMC) structure, which is suitable for packaging substrate integrated waveguide (SIW) filters to avoid external interference and loss caused by radiation and internal radiation leakage, the middle layer substrate provides a stable gap layer, and the base substrate is used to obtain a SIW filter by etching the slots in the metal plane and placing metallic via-holes in the middle of the layer, i.e. a self-packaged UWB ISGW filter. The proposed filter was fabricated and tested at a center frequency of 17.5 GHz as an example. The measurements show that the filter has a passband from 14.4 to 20.7 GHz, i.e. This filter has a fractional bandwidth (FBW) of 36%, and an insertion loss of 0.91 dB. More importantly, thanks to ISGW, two transmission zeros are obtained at 12.9 and 22.1 GHz to improve high selectivity.
关键词： packaging,Integrated substrate gap waveguide (ISGW),Bandpass filter (BPF),Ultra-wideband (UWB)
更新于2025-09-12 10:27:22
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Wideband Rectangular Double-Ring Nanoribbon Graphene-Based Antenna for Terahertz Communications
摘要： A wideband nanoribbon graphene-based antenna with double rectangular rings for terahertz (THz) applications is presented. The wideband and efficient graphene-based antenna on physical parameters is developed in this paper. The antenna has a wide impedance bandwidth of 26% at the center frequency of 1 THz, minimum return loss equal to 24 dB and average radiation efficiency approximately equal to 44% is obtained. An average gain of 2.45 dB is achieved at the operational frequency band. The goal of this paper is to provide an antenna with capabilities of being wideband, efficient and re-configurable with a simple and single-layer structure for THz communication.
关键词： Double-ring antenna,wideband antenna,graphene,terahertz,THz,re-con?gurable,nanoribbon antenna
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - Atlanta, GA, USA (2019.7.7-2019.7.12)] 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - An Offset-Fed Wideband 3D Printed Aperture Coupled Trapezoidal Dielectric Resonator Antenna
摘要： An offset-fed aperture coupled trapezoid shaped dielectric resonator antenna (DRA) is presented and investigated for wideband operation. In the first step, a square DRA is studied and then modified to a trapezoidal shape resonator, which achieves a wideband impedance bandwidth of 500 MHz. For potential operation as a dual-polarized antenna, an offset-feed system is implemented in the next stage. The offset-fed DRA achieves a bandwidth of 440 MHz centered at 2.45 GHz.
关键词： additive manufacturing,wideband,3D printing,antenna,dielectric resonator antenna
更新于2025-09-11 14:15:04