基于缺陷地结构的小型化双频带带通滤波器

提出了一种新型的基于缺陷地结构的双频带带通微带滤波器.缺陷地结构采用双模开口谐振环形式, 并使用不同组合方式的双模开口谐振环产生两个通带.滤波器的两个工作中心频率分别为3.5 GHz和5.8 GHz, 其中第一个频带涵盖了所有全球微波互联接入的应用频段, 第二个频带可以应用于雷达设备.为了进一步证实这款滤波器的性能, 基于Roggers RT5880板材制作了滤波器实物, 整体滤波器的大小仅为20 mm×20 mm, 测量数据和仿真结果吻合较好, 并且有两个传输零点, 可以满足工程上的需要.     

Ka频段宽带双口双模馈源设计

针对卡塞格伦天线系统对馈源的要求,设计了一种Ka频段双口双模馈源,可与X频段馈源组合成体积较小的双频段馈源。采用圆环状的和差比较器结构,降低了双频段馈源的体积,通过添加过渡阶梯、圆柱销钉与金属调配板等设计,改善了双频段馈源的性能。测试结果表明,在绝对带宽2 GHz范围内,S和口、E差口与H差口驻波比均小于2,3个端口间的隔离度均大于25 dB。测试频率的和方向图在±60°时的归一化增益均在-14~-20 dB范围内,初级归一化和方向图的对称性较理想,差方向图的零值深度均小于-25 dB,满足卡塞格伦天线对馈源设计的指标要求。     

A dual-mode complex filter for GNSS receivers with frequency tuning

A fifth/seventh order dual-mode OTA-C complex filter for global navigation satellite system receivers is implemented in a 0.18 fxm CMOS process. This filter can be configured as the narrow mode of a 4.4 MHz bandwidth center at 4.1 MHz or the wide mode of a 22 MHz bandwidth center at 15.42 MHz. A fully differential OTA with source degeneration is used to provide sufficient linearity. Furthermore, a ring CCO based frequency tuning scheme is proposed to reduce frequency variation. The measured results show that in narrow-band mode the image rejection ratio (IMRR) is 35 dB, the filter dissipates 0.8 mA from the 1.8 V power supply, and the out-of-band rejection is 50 dB at 6 MHz offset. In wide-band mode, IMRR is 28 dB and the filter dissipates 3.2 mA. The frequency tuning error is less than ±2%.     

Cysteamine-Gold Coated Carboxylated Fluorescent Nanoparticle Mediated Point-of-Care Dual-Modality Detection of the H5N1 Pathogenic Virus

Globally, point-of-care testing (POCT) is the most preferable on-site technique for disease detection and includes a rapid diagnostic test (RDT) and fluorescent immunochromatographic strip test (FICT). The testing kits are generally insufficient in terms of signal enhancement, which is a major drawback of this approach. Sensitive and timely on-site POCT methods with high signal enhancement are therefore essential for the accurate diagnosis of infectious diseases. Herein, we prepare cysteamine-gold coated carboxylated europium chelated nanoparticle (Cys Au-EuNPs)-mediated POCT for the detection of the H5N1 avian influenza virus (AIV). Commercial nanoparticles were used for comparison. The spectral characteristics, surface morphologies, functional groups, surface charge and stability of the Cys AuNPs, EuNPs, and Cys Au-EuNPs were confirmed by UV-visible spectrophotometry, fluorescence spectrometry, transmission electron microscope with Selected area electron diffraction (TEM-SAED), Fourier-transform infrared spectroscopy (FTIR) and zeta potential analysis. The particle size distribution revealed an average size of ~130 ± 0.66 nm for the Cys Au-EuNPs. The Cys Au-EuNP-mediated RDT (colorimetric analysis) and FICT kit revealed a limit of detection (LOD) of 10 HAU/mL and 2.5 HAU/mL, respectively, for H5N1 under different titer conditions. The obtained LOD is eight-fold that of commercial nanoparticle conjugates. The photo luminance (PL) stability of ~3% the Cys Au-EuNPs conjugates that was obtained under UV light irradiation differs considerably from that of the commercial nanoparticle conjugates. Overall, the developed Cys Au-EuNPs-mediated dual-mode POCT kit can be used as an effective nanocomposite for the development of on-site monitoring systems for infectious disease surveillance.     

基于忆阻器的可切换带通滤波器

将忆阻器作为射频开关,采用传统双模谐振器与改进式短路阶跃阻抗谐振器的组合结构,设计了一款可切换的三频带通滤波器.通过合理设计忆阻器偏置电路的位置,利用忆阻器阻抗的非易失性来实现滤波器通带的可切换功能.当滤波器工作时忆阻器处于断电的记忆状态,从而改善了可切换滤波器的互调性能.文中设计的滤波器拥有四种可切换工作状态,包括三...     

圆形开槽贴片微带双模带通滤波器

提出了一种新颖、简单的圆形贴片上刻蚀小方槽的微带双模带通滤波器结构.该滤波器仿真的通带中心频率为5.9 GHz,最大回波损耗优于-31.5 dB,通带内最小插入损耗为- 0.7 dB,3 dB带宽为23.73％.实测和仿真结果相一致.     

Millimeter-Wave Ultra-Wideband Bandpass Filter Employing Dual-Mode Ring Resonators Fed by Step-Impedance Coupled Lines

This paper presents a novel millimeter-wave ultra-wideband (UWB) bandpass filter (BPF) based on microstrip dual-mode rectangular ring resonators. In order to get strong coupling between the input/output line and the dual-mode ring resonators, a step-impedance parallel-coupled structure is adopted for the design of the filter. On the other hand, transmission zeros are produced by the dual-mode resonator. As a consequence, the filter has low insertion-loss in its passband, sharp attenuation in its lower and upper stopbands and very wide stopbands. As an example, a filter with two dual-mode ring resonators is designed and fabricated. The measured frequency property of the fabricated filter shows good agreement with the simulated response.     

一种抵抗水声信道多途干扰的新的盲均衡算法

由于在时变水声信道中会产生随机相位失真，CMA算法的误码性能严重下降。在双模式盲均衡算法的基础上，提出了一种适用于水声信道的新的盲均衡算法——NCMA算法。计算机仿真结果表明，在时变水声信道中，该算法性能优于双模式算法，能够达到对信号相位失真的恢复，并且收敛性能优于双模式算法。     

（英）基于新型双模圆谐振腔的高选择性毫米波滤波器

提出了一种新颖的高选择性毫米波带通滤波器及其设计方法.在圆谐振腔的侧壁加入槽型微扰结构,通过调节微扰小槽的角度可以控制滤波器带外传输零点的位置,从而实现了带宽可调、高选择性的双模圆谐振腔带通滤波器.根据该滤波器结构、理论分析和仿真设计基础,研制了在V波段滤波器样品并进行了测试.实验结果与方正吻合得良好.与传统双模圆腔滤波器相比,所提出的滤波器不需要额外的调节结构,其设计方法简单,选择特性高,结构紧凑,具有一定的工程价值用于高性能平面化毫米波滤波器的设计.     

椭圆芯双模光纤在电压传感器中的应用与研究

文章简要介绍了双模光纤中存在的传输模式,讨论了椭圆芯双模光纤模斑稳定性。建立在光纤中传输模场的基础上,研究了两模间干涉特性和传感特性，指出了远场两瓣光斑的动态变化规律.针对不同的扰动,重点讨论了轴向应变、径向应变和温度变化对模间相位差的影响，分析了基于逆压电效应的双模光纤电压传感器结构和原理,以及信号的获取。