Miniaturized Planar Ultra-Wideband Bandpass Filter with Notched Band

This paper presents a planar ultra-wideband (UWB) bandpass filter with sharp out-of-band rejection performance. The filter is formed by a folded multiple-mode resonator to realize high performance in an operation band from 3.3 to 10 GHz with a very compact size of 20 mm × 20 mm × 0.5 mm. An extra notched band centered at 5.8 GHz is further accomplished by etching a Hilbert fractal curve slit on the filter without the necessity of readjusting the geometrical parameters. The simulated and measured results are in good agreement.

High-confinement ultra-wideband bandpass filter using compact folded slotline spoof surface plasmon polaritons

A novel bandpass filter(BPF)based on spoof surface plasmon polaritons(SSPPs)using a compact folded slotline structure is proposed and experimentally demonstrated.The proposed novel SSPPs structure compared with a conventional plasmonic waveguide with slot line SSPPs unit structure at the same size,the considerable advantages in much lower asymptotic frequency with tight field confinement,which enable the proposed filter to be more miniaturization.A high-efficient mode conversion structure is designed to transition from TE-mode to SSPPs-mode by gradient slotline lengths.The low-frequency stop-band can be committed with microstrip to slotline evolution on both sides of the dielectric,while the high-frequency cutoff band is realized by the proposed SSPPs structure.The influence of dispersion relation,electric field distribution,surface current,and structural parameters on the transmission characteristics of the proposed BPF are analyzed by finite difference time domain(FDTD).To validate the design concept,the prototype of the miniaturized SSPPs BPF has been manufactured and measured.The experimental results show high performance of the fabricated sample,in which the working in a range of 0.9 GHz-5.2 GHz with the relative bandwidth is 142%,the insertion loss less than 0.5 dB,the reflection coefficient less than-10 dB,and the group delay is less than one ns.This works provides a mirror for realizing the miniaturization of waveguides,and the application and development of high-confinement SSPPs functional devices in the microwave and THz regimes.

Design and simulation of a compact ultra-wideband bandpass filter with a notched band using multiple-mode resonator technique

A novel, compact, and highly selective ultra-wideband （UWB） bandpass filter with a narrow notched band is presented. Apart from having a basic structure of a slotline multiple-mode resonator （MMR） and microstrip feed lines, this novel design introduces a cross-coupling between the input and output feed lines to enhance the filter selectivity. The design strictly follows the theory and verified by electromagnetic （EM） simulation and experiments. In addition, the narrow notched band is introduced by embedding a pair of split ring resonators （SRR） in order to reject any undesired existing radio signals that may interfere with the Federal Communications Commission （FCC）-defined UWB band. By changing the structural parameters of SRR, it can be easily tuned to any desired frequency. This filter can be integrated in UWB communication systems and efficiently improve the interference immunity from undesired signals such as wireless local area network （WLAN）.

Development of Compact Ultra-Wideband (UWB) Microstrip Bandpass Filter

Miniaturized Ultra-Wideband (UWB) microstrip bandpass filter with wide passband is presented. The filter is developed based on modified multiple mode resonator, which is formed by transversely attaching three pairs of non-uniform and folded stubs with lowpass and highpass sections. Both sides of high-impedance section are linked with two feed lines via direct coupled lines, resulting UWB bandpass filter. The designed filter provides 7 GHz passband between 2.5 and 9.5 GHz with approximately, –0.5 dB insertion loss, –35 dB minimum return loss at 6.85 GHz, linear phase over the passband and 110% of fractional bandwidth at –3 dB. The computed group delay variation in the passband for the filter is 0.02 ns. The overall dimension of the filter is 10.7 mm (length) × 3 mm (width) × 1.6 mm (thickness).

Ultra-wideband surface plasmonic bandpass filter with extremely wide upper-band rejection

An ultra-wideband bandpass filter(BPF)with a wide out-of-band rejection based on a surface plasmonic waveguide(SPW)slotline with ring grooves is designed and analyzed.A paired microstrip-to-slotline transition is designed for quasiTEM to TM mode conversion by using a microstrip line with a circular pad and the slotline with the same circular slot.The mode conversion between the TM and the surface plasmon polariton(SPP)mode is realized by using a gradient slotline with ring grooves and an impedance matching technique.The upper cut-off frequencies of the passband can be adjusted by using these proposed SPP units,while the lower frequencies of the passband are created by using the microstrip-toslotline transitions to give an ultra-wideband BPF.The dispersion curves of SPP units,electric field distribution,and the transmission spectra of the proposed ultra-wideband bandpass filter are all calculated and analyzed by the finite-difference time-domain(FDTD)method.The simulated results show that the presented filter has good performance including a wide3-dB bandwidth of 149%from 0.57 GHz to 3.93 GHz,an extremely wide 40-dB upper-band rejection from 4.2 GHz to18.5 GHz,and low loss and high selectivity in the passband.To prove the design validity,a prototype of the BPF has been manufactured and measured,showing a reasonable agreement with simulation results.The unique features of the proposed BPF may make it applicable for integrated circuit and plasmonic devices in microwave or THz frequency ranges.

5G Wideband Bandpass Filtering Power Amplifiers Based on a Bandwidth-Extended Bandpass Matching Network

In this paper,a 5G wideband power amplifier(PA)with bandpass filtering response is synthesized using a bandwidth-extended bandpass filter as the matching network(MN).In this structure,the bandwidth(θ_(C))is defined as a variable in the closedform equations provided by the microstrip bandpass filter.It can be extended over a wide range only by changing the characteristic impedances of the structure.Different from the other wideband MNs,the extension of bandwidth does not increase the complexity of the structure(order n is fixed).In addition,based on the bandwidth-extended structure,the wideband design of bandpass filtering PA is not limited to the fixed bandwidth of the specific filter structure.The theoretical analysis of the MN and the design flow of the PA are provided in this design.The fabricated bandpass filtering PA can support almost one-octave bandwidth(2-3.8 GHz),covering the two 5G bands(n41 and n78).The drain efficiency of 47%-60%and output power higher than 40 dBm are measured.Good frequency selectivity in S-parameter measurements can be observed.

小型化低剖面全向滤波天线设计

设计了一个小型化全向微带滤波天线。天线由带通滤波器和微带天线组成,二者共用一个地平面以减小尺寸且采用缝隙耦合方式连接,带通滤波器蚀刻在微带贴片天线的馈线位置处,引入选频滤波功能,在输入馈线前端添加一个横向矩形贴片使整个系统达到良好的阻抗匹配。与传统的微带天线相比,所设计的滤波天线在不改变尺寸大小的基础上引入了选频滤波功能,在通带边缘体现出较高的选择性。仿真与测试结果表明,该滤波天线的阻抗带宽为2.31 GHz~2.56 GHz,且通带内增益平缓,平均增益约为2.1 dBi,在工作频段内呈全向辐射特性。

低噪声水声信号前置放大器设计

水下信息的发送与接收主要通过声信号的传播,水听器作为常用的水声信号接收装置,需要前置放大器来提高所获取信号的质量。文中选用AD8421仪表放大器芯片与OP2177精密运算放大器芯片设计了一种低噪声水声信号前置放大器,该电路增益为26 dB,工作带宽为100 Hz~20 kHz,输出信号为差分形式,同时具有小体积、低功耗的特点。通过连接某型压电水听器,测试了电路工作性能以及对水听器信号的调理效果。实测结果表明,该前置放大器能满足设计技术指标要求,在实际工作中取得了良好的效果。

基于阶跃阻抗谐振器的四阶频率可调滤波器设计

提出一种基于阶跃阻抗谐振器的紧凑型四阶四零点频率可调滤波器设计。滤波器使用变容二极管加载的阶跃阻抗谐振器(VL-SIR),有效拓宽了滤波器的调谐范围。在VL-SIR之间引入交叉耦合,从而在滤波器通带近端产生一对传输零点,显著提高了滤波器的选择性。同时,引入源和负载端的交叉耦合,在通带远端生成一对传输零点,以提高带外抑制。此外,采用基于VL-SIR的频变耦合结构来实现恒定绝对带宽。仿真结果与实测结果吻合良好。测量结果显示,可调滤波器频率调谐范围为0.78~1.15 GHz,3 dB绝对带宽约为55±3 MHz,滤波器的回波损耗大于10 dB,插入损耗约为2.8~3.3 dB。

基于卷积神经网络的微带滤波器的参数预测

提出了一种基于卷积神经网络的微带带通滤波器的参数预测方法,针对一个三频带带通滤波器进行预测。首先利用HFSS电磁仿真软件训练数据得到S参数的数据集作为真实值数据集,将微带滤波器的S参数作为输入,物理结构参数作为输出,通过卷积神经网络进行训练,最后将目标S参数作为输入进行参数预测。相比于简单的全连接神经网络,卷积神经网络不仅能够大幅度地减少网络参数,还有效避免了过拟合情况的出现,解决了全连接神经网络耗时长的问题,并且由于卷积神经网络对于结构参数的预测是直接的,即使对于初学者也可以节省大量设计时间。仿真结果表明,目标S参数与卷积神经网络预测后得到的S参数拟合程度很高,证明了该方法对微带滤波器物理结构参数的预测有较高的准确率。

一种近似芯片级尺寸的小型化微带点频滤波器

射频滤波器作为具备信号筛选功能的射频器件,对现代通信系统而言具有举足轻重的地位。随着通信技术的不断更新迭代,要求射频滤波器具有小型化以及低成本的特点。目前,利用半导体工艺可制作尺寸极小且性能佳的芯片级滤波器,但研发成本普遍过高。文中使用薄膜工艺,通过对滤波器的结构、材料、性能指标进行综合考量,设计了一款适用于点频源、跳频源模块中使用的微带点频滤波器。通过仿真软件HFSS进行建模仿真并对加工工艺进行误差分析,成功得到了一款通带在12 GHz±15 MHz的微带点频滤波器,其尺寸为2.5 mm×3.5 mm×0.127 mm。测试结果表明,性能曲线达到设计指标,成功验证了设计的可行性。

基于HMSIW的小型化三模带通滤波器设计

传统的多模谐振器引入多个谐振器,并利用其中两个甚至多个谐振模式来组合构建滤波器通带,但由于其谐振器个数较多而在射频系统中占用了较大的空间。为此,本文提出了基于半圆形半模基片集成波导(HMSIW)的三模带通滤波器,通过引入金属化过孔来扰动半圆形HMSIW谐振腔的谐振模式的电场分布,使得对应的谐振模式的频率也会随之发生偏移,进而使原本谐振频率相差较大的三个谐振模式的频率逐渐靠近,最终组合形成滤波器的通带。该设计无需引入额外的谐振器,能够实现滤波器尺寸减半甚至成倍减少,从而达成小型化的目的。

基于悬置微带结构的无反射滤波器

通过悬置微带传输线结构进行了无反射滤波器的研究和设计。首先利用耦合线结构设计了中心频率为3.92 GHz,插入损耗为0.32 dB,在0.1~10 GHz内回波损耗超过11.6 dB,中心频率处超过38 dB的双端口无反射带通滤波器;又利用λ/4开路谐振器和λ/4短路谐振器作为滤波单元,设计了中心频率为4.25 GHz,回波损耗在1.5~6 GHz内超过11 dB,在中心频率处超过40 dB的双端口无反射带阻滤波器。所提出的这两款无反射滤波器具有无反射频带范围宽、工作频带内S_(11)衰减大、多层自封装等突出优点。

Maximum Correntropy Criterion-Based UKF for Loosely Coupling INS and UWB in Indoor Localization

Indoor positioning is a key technology in today’s intelligent environments,and it plays a crucial role in many application areas.This paper proposed an unscented Kalman filter(UKF)based on the maximum correntropy criterion(MCC)instead of the minimummean square error criterion(MMSE).This innovative approach is applied to the loose coupling of the Inertial Navigation System(INS)and Ultra-Wideband(UWB).By introducing the maximum correntropy criterion,the MCCUKF algorithm dynamically adjusts the covariance matrices of the system noise and the measurement noise,thus enhancing its adaptability to diverse environmental localization requirements.Particularly in the presence of non-Gaussian noise,especially heavy-tailed noise,the MCCUKF exhibits superior accuracy and robustness compared to the traditional UKF.The method initially generates an estimate of the predicted state and covariance matrix through the unscented transform(UT)and then recharacterizes the measurement information using a nonlinear regression method at the cost of theMCC.Subsequently,the state and covariance matrices of the filter are updated by employing the unscented transformation on the measurement equations.Moreover,to mitigate the influence of non-line-of-sight(NLOS)errors positioning accuracy,this paper proposes a k-medoid clustering algorithm based on bisection k-means(Bikmeans).This algorithm preprocesses the UWB distance measurements to yield a more precise position estimation.Simulation results demonstrate that MCCUKF is robust to the uncertainty of UWB and realizes stable integration of INS and UWB systems.

基于FPGA的数字带通滤波器设计与仿真

为快速准确地提取超声导波信号中的目标信息,采用流水线加法树阵列结构设计低阶滤波器,采用直接型低阶叠加实现20阶高精度带通滤波器。运用流水线技术与FPGA片上资源相结合实现对该结构数字算法优化,并将其应用在镍铬合金超声导波测温系统中。结果表明:所设计的滤波器对512点的混频超声导波信号滤波耗时约1047个时钟。该滤波器总体设计简单,可以达到实时滤波的功能。

多器件联合L波段强电磁脉冲防护模块仿真设计

目的设计针对L波段射频前端敏感器件的强电磁脉冲防护模块,利用瞬态电压抑制二极管、气体放电管和发夹型微带带通滤波器进行联合仿真设计。方法瞬态电压抑制二极管具有快速响应时间,气体放电管具有高功率容量,而微带带通滤波器可分离噪声信号,并保留有效信号。通过结合这些器件进行防护设计,可以充分发挥各自优势,提高系统稳定性和强电磁脉冲防护能力。结果该模块设计工作频段为1.3~1.7GHz,带内插入损耗小于1.5dB,在70dBm功率注入的情况下,防护效果可以达到42.5dB,具有良好的防护效果。结论通过分析研究不同器件的特性和优化设计,实现了对L波段频谱的防护,具有重要的实用价值和广阔的应用前景。

应用于WIFI或BLE接收机可重构有源RC滤波器设计

文中提出一种可重构的有源RC滤波器,其可以同时适用于WIFI6/BLE(低功耗蓝牙)传输协议。该滤波器基于40nm CMOS工艺设计,其可以在五阶切比雪夫低通滤波器与三阶巴特沃斯复数带通滤波器进行切换,并基于可编程的电阻和电容,实现增益和带宽的调节。为了满足高截止频率(80MHz)的场景,以及相应的带宽精度,滤波器使用一种基于新补偿技术的新型全差分运算放大器,并采用PTAT电流,该放大器优化了滤波器高频性能并最大限度地减少了电流消耗。版图后仿真结果表明,在WIFI应用中,滤波器的典型带宽为10、20、40、80 MHz,增益调节范围0~24 dB,单路电流消耗为2、3、4.5、5.1 mA,拥有出色的相邻信道抑制:-36 dB@160 MHz(80 MHz带宽);BLE模式下,中心频率可在1 MHz和2 MHz之间进行切换,并拥有大于30dB的镜像抑制,增益0~24 dB可调,单路功耗为1.2 mA。

2021年辽宁西部两次暴雨过程典型特征对比

基于常规气象观测资料和ERA5再分析数据,利用Barnes带通滤波法,借鉴计算地形阻挡气流上升高度的方法,对辽宁西部地区2021年6月下旬到7月中旬发生的两次暴雨过程(简称“6·27”暴雨“、7·13”暴雨)进行分析。结果表明:两次暴雨过程降水中心均位于北镇市,高空均有冷涡生成,下游高压脊阻挡冷涡东移,低空急流带来的暖湿水汽通过南边界流入暴雨区,975 h Pa均存在风速辐合线和中尺度气旋式辐合中心。由于高空冷涡、下游高压脊、低空急流、对流不稳定强弱不同,以及975 hPa风速辐合线、中尺度气旋式辐合中心、850 hPa低空急流和地面中尺度辐合线的配置不同,导致“6·27”暴雨局地性强,降水时段集中,雨强偏大,而“7·13”暴雨影响范围较大,降水时段较分散,强降水维持时间长,雨强偏小。从雷达特征上看,降水最强时,“6·27”暴雨影响北镇的是低质心高效率降水回波,对流云区维持时间较长“;7·13”暴雨是高质心降水回波,对流云区维持时间较短,因此“6·27”暴雨雨强较大,北镇最大小时雨强达68 mm。

基于InP HEMT的太赫兹分谐波混频器芯片设计

基于70 nm InP高电子迁移率晶体管(HEMT)工艺,研制了一款175~205 GHz分谐波混频器太赫兹单片集成电路(TMIC)。使用三线耦合Marchand巴伦实现本振信号的平衡-不平衡转换。在射频端口设计了紧凑型耦合线结构的带通滤波器,实现对射频信号低损耗带通传输的同时缩小了芯片尺寸。测试结果表明混频器在175~205 GHz频率范围内,单边带(SSB)变频损耗小于15 dB,典型值14 dB。混频器中频频带为DC~25 GHz,射频端口对本振二次谐波信号的隔离度大于20 dB。芯片尺寸为1.40 mm×0.97 mm,能够与相同工艺的功率放大器、低噪声放大器实现片上集成,从而满足太赫兹通信等不同领域的应用需求。

一种低噪声水声信号电路设计

文章主要介绍一种水听器信号处理电路,主要包括前放电路、四阶带通滤波电路以及放大电路。该电路采用ADI公司的低噪声、低功耗的AD8605和AD8608芯片,该电路的增益为60 dB,滤波带宽为200 Hz,等效电容输入噪声低。通过对水声信号进行放大和滤波,能够有效地从噪声信号中提取出目标信号。