Switched-capacitor bandpass filter with quasi-continuous digitalQ-factor tunability

A second-order switched-capacitor (SC) bandpass filter with very wide Q-factor programmability range, is presented. Although the Q-factor is controlled by digitally varying the effective sampling frequency of an SC branch, quasi-continuous programmability is provided. Experimental results from a 0.8 μm CMOS integrated prototype demonstrate the versatility of the proposed technique     

交叉耦合带通滤波器的优化研究及仿真

第五代移动通信技术对系统的滤波性能有着更高的要求,所以滤波器的优化是保障系统性能的关键所在。首先通过对滤波器函数多项式的损耗分析,推导出各项滤波指标与谐振器无载Q值之间的函数关系,并在一定的拓扑结构中进行仿真验证。然后对每个谐振器无载Q值进行补偿仿真,通过采用高Q值谐振器的方法,使通带边频点的损耗及响应曲线得到改善,最终实现滤波器优化设计的目标。     

超高频带通滤波器的设计与仿真

介绍一种在理论计算的基础上,采用ADS软件对射频滤波器进行优化及仿真的方法,重点阐述射频滤波器设计过程中的优化设计、器件仿真以及矩量法分析等相关内容。射频滤波器的测试结果表明其通带内波纹小于3dB,带内输入输出端口反射系数小于-20 dB,阻带衰减大于40 dB,相比于传统设计方法,此方法具有可行性和有效性。     

基于Filterlab的一种高指标带通滤波器的设计

为了提取激光外差玻璃测厚系统中的微弱信号,介绍了激光外差玻璃厚度测量系统原理及待检测信号特征,采用一种简洁、实用的滤波软件,设计出一种高指标带通滤波器,从滤波器频谱图看待检测的激光外差信号频谱完全在通频带内,噪声衰减带达到80 dB,其完全符合系统要求。     

A compact triple-band bandpass filter based on metamaterials

This paper presents a compact triple-band bandpass filter based on metamaterials. The miniaturization is realized by the principle of phase compensation of metamaterial. Compared with the conventional half-wavelength filter, the metamaterial filter has a small size of 10 mm×10 mm. The triple-band bandpass filter performance has been validated by the electromagnetic simulation software of high frequency structure simulator(HFSS). The results illustrate that the filter is designed with center frequencies of 2.4 GHz, 5.1 GHz and 8.8 GHz, bandwidths of about 7.9%(2.31—2.50 GHz), 7.8%(5.0—5.4 GHz) and 7.4%(8.50—9.15 GHz), respectively, and it shows good band pass characteristics.     

Compact resonant bandpass filter based on PBG structure

A new resonant bandpass filter based on a photonic band gap (PBG) structure is designed and optimised. The finite-difference time-domain method is applied to characterise the proposed filter. The filter is much easier to fabricate, more compact and simpler to design than the conventional parallel-coupled line filter, has wide stopband and steep and deep upper bandstop. The filter length is about one guiding wavelength (/spl lambda/e). A semiconductor-based structure is realised using microelectronics technology and good agreement between the experimental and simulation results has been achieved.     

Current controlled bandpass filter based on translinear conveyors

A new concept to take advantage of the parasitic resistance that appears on port X of the second-generation current conveyors is introduced. This parasitic resistance, which is controllable in current, leads to the definition of the second generation current controlled conveyors (CCCII). A current controlled bandpass filter, operating in the current mode, is also described. It uses only two CCCII's and two capacitors. Its central frequency can be adjusted by acting on the bias current of the conveyors. SPICE simulation results, in agreement with theory, are given for central frequencies around 30 MHz     

Tunable bandpass filter based on capacitor-loaded metamaterial lines

A bandpass filter is constructed by loading a left-handed metamaterial transmission line with an additional shunt capacitor. The shunt capacitor provides more freedom to control the passband characteristics of the resulting metamaterial line. A bandpass filter is designed with a centre frequency that is tunable from 0.45 to 0.65 GHz.     

基于新型CCCⅡ电流模式二阶带通滤波器设计

针对传统第二代电流传输器(CCⅡ)电压跟随不理想的问题,提出了新型第二代电流传输器(CCCⅡ)并通过采用新型第二代电流传输器(CCCⅡ)构成二阶电流模式带通滤波器,此滤波器只需使用2个电流传输器和2个电容即可完成设计。设计结构简单,其中心频率可由电流传输器的偏置电流控制。利用HSpice软件仿真分析并验证了理论设计的准确性和可行性。     

基于C型DGS的双通带滤波器设计

基于环形谐振器的基础结构,提出了新型C型缺陷地结构(defected ground structure,DGS)的双通带滤波器。利用C型DGS结构的高阻抗传输线特性,通过调节C型DGS结构的长度与宽度尺寸,可以实现对双频段带通滤波器的工作频段控制。最后给出了一个2.4 GHz和3.45 GHz工作频段的微带双通带滤波器设计实例,其测试结果与仿真结果吻合。     

基于数学优化法的带通滤波器研究

提出了在滤波器设计过程中的一种数学优化设计方法。理论分析表明,该设计方法能够通过设定目标函数和约束条件的方式迅速而准确地逼近目标,接近理想响应。基于该分析,分别用插入损耗法和数学优化法设计了一个等波纹电感耦合带通滤波器。仿真结果表明:使用数学优化法不仅可以快速而准确地进行设计,而且能大幅提升滤波器性能。     

Reconfigurable multilayer dual-mode bandpass filter based on memristive switch

A novel memristor-based multilayer dual-mode resonator is presented, which is suitable for the design of reconfigurable multi-band filters. The memristor is used as an RF/microwave switch. A dual-band bandpass filter is realized with the proposed memristor-based dual-mode resonators. The corresponding memristor setup circuitry is optimized in order to minimize the circuitry influence on the desired filter frequency response.     

基于多向馈电耦合的折叠小型化三带通滤波器

基于奇偶模理论,通过多向馈电耦合的方式,在十字形双频带通滤波器(DBPF)的基础上,研究并设计了一种十字形枝节折叠的双馈线三通带通滤波器(TBPF)模型。结构分析表明,该模型具有三频中心频率灵活独立可调,结构易级联,小型化和频率设计参量少的特点。仿真结果表明,增加的馈电方向激励起滤波器的第三通带,设计的TBPF在5G通信的中低频段和室内WiFi低频段具有良好的特性。文献比较显示,提出采用的多向馈电设计方法,减少了谐振器结构复杂度和频率设计参数个数,同时,该法对基础谐振器通带频段的增加有一定启示意义。     

Novel all-fiber bandpass filter based on hollow optical fiber

We report an in-line all-fiber bandpass filter based on a hollow optical fiber (HOF) core mode blocker along with a long-period fiber grating (LPG) pair. It is theoretically and experimentally confirmed that selective core mode blocking at the HOF region located in the middle of the LPG pair could provide efficient passband channels corresponding to the resonant wavelengths of the LPGs. The filter characteristics in passbands and the nearfield patterns of guided modes in the proposed device are discussed.     

基于SISL的介质填充双通带滤波器设计

为实现滤波器的小型化,基于介质集成悬置线(substrate integrated suspended line, SISL)结构提出了一种介质填充双通带滤波器的设计方案. 首先将高介电常数的介质块填充入SISL的空气腔中,提升SISL的等效介电常数,实现电路的小型化,高介电常数介质块可以直接被SISL固定;然后利用T型结连接两组工作在不同频段的滤波器从而使得两个通带相对独立;最后利用仿真软件进行优化,确定介质填充双通带滤波器的尺寸,并进行加工与测试. 仿真与测试结果表明,二者具有较好的一致性,两个通带频率内的回波损耗均优于15 dB,电路的核心尺寸为0.058λ_g×0.139λ_g(λ_g为SISL在第一通带中心频率处的导波波长). 此双通带滤波器具有小尺寸、自封装等优势,且所有层介质基板均采用低成本的FR4板材,降低了制造成本.     

Highly selective bandpass filter based on substrate integrated waveguide

A novel highly selective six-pole elliptic filter based on a substrate integrated waveguide (SIW) is proposed for the first time. The filter is composed of two planar SIW extend doublets. The modular design approach based on cascading small building blocks is adopted to reduce the effect of manufacturing tolerance on the performance of the filter. The proposed filter can produce four finite transmission zeros, and has an excellent stopband rejection characteristic. Measured results are presented and compared with results simulated by a high frequency structure simulator. Good agreement between simulated and measured results is observed.     

基于SGS的UWB滤波器设计

在传统哑铃型缺陷接地结构(defected ground structure,DGS)的基础上,提出了一种分割地结构(split ground structure),通过在传统哑铃型DGS上添加一条缝,形成了SGS结构,不仅有低通特性,而且产生了高通特性,即具有带通特性。借助于HFSS软件,比较了传统哑铃型DGS与SGS的仿真结果,分析了SGS结构参数变化对其频率特性的影响。并以此为基础设计了一种新颖的超宽带(UWB)带通滤波器,中心频率6.85 GHz,相对带宽110%,上边带20 dB阻带抑制达20 GHz。仿真结果表明,该滤波器具有较好的频率特性,说明基于SGS的UWB带通滤波器设计的有效性和可行性。     

基于FPGA的罗兰C前端IIR数字带通滤波器设计

针对罗兰C前端带通滤波的需求,提出了采用级联形式在FPGA上实现罗兰C数字带通滤波器的方法。首先利用Matlab设计出满足要求的滤波器,考虑硬件设计要求将参数进行取整,并对取整前后的滤波效果进行了比对分析。在硬件程序设计前在Matlab下用级联式差分方程模拟硬件滤波算法,以提高设计的成功率。最后在FPGA下用Veril...     

一种基于微带开口环的双通带滤波器设计

文中提出了一种基于微带开口环的双通带滤波器设计,对比了非对称开口环结构与传统对称结构的传输特性,讨论了非对称结构中两端馈线位置,双环耦合间距以及环线宽度对于滤波器性能的影响,然后在此基础上,利用两级级联耦合开口环设计了一个用于接收机中抑制镜像的双通带滤波器,带外抑制度较高。     

基于人工表面等离子体激元带通滤波器的设计

设计了基于人工表面等离子体激元(spoof surface plasmon polaritons,spoof SPPs)的带通滤波器,在介质基板上覆上一层超薄金属铜,并将金属表面刻为周期波纹状金属条,同时结合马赫曾德尔干涉仪(Mach–Zehnder interferometer,MZI),将金属条设计为MZI结构,并对MZI的干涉臂设计了两个取向相反的金属条结构,构成滤波器耦合部分,分析了耦合间距以及耦合单元个数对带通滤波器带宽的影响并进行了仿真。结果表明,该滤波器具有–3 d B从4.8 GHz到8.3 GHz的带宽。基于人工等离子体激元的带通滤波器的设计为今后人工表面等离子体在微波行业的应用提供了思路。