交指带通滤波器的精确设计

用数据表综合出交指带通滤波器的初始值,然后用德国的三维高频电磁仿真软件CST4.2进行仿真,提高了设计效率和精度.并给出了交指型带通滤波器的设计实例,仿真结果表明研制出的滤波器的性能和理论值基本一致.     

一种新型交指-发夹型多层带状线带通滤波器

提出了一种新型交指－发夹型多层带状线带通滤波器结构,并设计加工了一个中心频率为2.25GHz,分数带宽为31%的四级带通滤波器,测试值与仿真值吻合得较好.通过仿真结果比较以及实验结果证明,与传统交指型带通滤波器相比,新型交指－发夹型滤波器不但体积减小了约一半,而且能够方便地引入交叉耦合,从而在阻带内产生传输零点,很好地改善滤波器的频率选择特性.     

一种微带交指型滤波器的改良型设计

论述了用Ansoft公司的Designer微波设计软件设计一种改良型的微带交指型带通滤波器。描述了微带交指型滤波器的设计方法,通过实例对这种改良型的微带交指带通滤波器进行了计算机最优化仿真设计,并给出了优化结果。微带交指型滤波器结构紧凑、指标优良,是微波混合集成电路中常见的形式,原理上是由1/4波长平行耦合线滤波器的谐振器折叠而成。     

一种新型SIR交指微带带通滤波器的设计

交指带通滤波器是工程应用中常用的带通滤波器,但随着产品的小型化及带外抑制性能要求的多样化,常规交指带通滤波器在使用上受到较多限制。文中设计了一种新型SIR交指型微带带通滤波器结构,对常规交指微带带通滤波器进行小型化以及抑制性能优化。这种滤波器通过引入1 4波长SIR结构缩小单个谐振单元尺寸进行小型化,并引入发夹结构,通过其自身谐振特性以及交叉耦合在左端引入一传输零点,达到改善抑制性能的目的。通过HFSS建模仿真比对了同指标的两种结构滤波器特性,分析得出各自适用的抑制要求。测试结果表明,设计的带通滤波器性能曲线与仿真曲线相吻合,符合设计要求。     

一种交指型带通滤波器的设计

本文介绍了交指型带通滤波器一种设计思路。通过一个设计实例。并且利用计算机软件对其进行仿真，测量结果与仿真结果基本吻合，这种方法设计的交指型带通滤波器具有通带平坦，插损小，精度高的优点。     

圆杆交指型滤波器的设计

介绍了圆杆交指型带通滤波器的设计原理和方法,根据交指滤波器的设计理论获得圆杆的自电容和互电容,利用计算机辅助设计工具进行数值计算,结合图表得到滤波器的最初尺寸。给出了一个中心频率为830 MHz圆杆交指滤波器的设计过程,利用HFSS软件仿真,提高了设计效率和精度,仿真结果和理论结果吻合良好,证明了设计方法的可行性。     

应用于RFID技术中交指型微带带通滤波器的设计

基于RFID技术中对小型化滤波器的需求,首先从理论上对小型化程度更高的微带交指型带通滤波器的滤波特性进行了分析,接着使用微波仿真软件ADS对微带交指型带通滤波器进行仿真,仿真时根据设计指标用ADS的优化功能对原理图进行多次优化,优化时对参数实行逐个优化法,使得优化速度更快.通过对一中心频率为2.45 GHz带宽为9%的...     

LTCC宽边耦合交指型超宽带滤波器设计

提出用交指型结构实现超宽带（UWB）带通滤波器的小型化,并给出了设计方法。该结构通过宽边耦合实现超宽带滤波器需要的较大耦合系数,并通过加宽带状线谐振器的宽度减少不必要的交叉耦合,简化了滤波器的设计。最终设计了一个中心频率为f0,相对带宽为58%的六阶交指带通滤波器,滤波器尺寸仅为8 mm×11 mm。从仿真结果看,该滤波器保持了传统交指型滤波器阻带特性好,寄生通带远的优点。     

一种抽头式交指带通滤波器的设计及实现

传统的交指带通滤波器设计采用公式计算归一化自电容和互电容,并通过查表计算得到滤波器的参数,该方法计算繁琐,且计算误差较大.文中介绍了一种根据谐振器的直接耦合原理,利用两终端的外部品质因数Q和谐振器间的耦合系数K设计抽头式交指型带通滤波器的方法.据此,设计了一种用于微波选频的交指滤波器,借助ADS软件对滤波器进行仿真和优化.通过仿真及实测结果的分析对比,进一步给出了设计改进方案.     

一种带传输零点交指带通滤波器的设计

通过在带状线交指滤波器的输入端并联一个λ／4开路谐振器,构成了一种改进型的交指带通滤波器。该滤波器在阻带特定频率处产生传输零点,且该零点位置可任意选择,较大地改善了滤波器带外的抑制。结合ADS仿真软件设计了一个C波段带传输零点的带状线交指滤波器,仿真结果表明,该方法可行有效,适合于工程应用。     

The analysis and design of two-dimensional nearly-orthogonal symmetric wavelet filter banks

The design and analysis of two-channel two-dimensional (2D) nonseparable nearly-orthogonal symmetric wavelet filter banks with quincunx decimation is studied. The basic idea is to impose multiple zeros at the aliasing frequency to a symmetric filter and minimize the deviation of the filter satisfying the orthogonal condition to obtain a nearly-orthogonal FIR filter bank. Since multiple zeros are imposed, a scaling function may be generated from the minimized filter. With this filter, a semi-orthogonal filter bank is constructed. Methods for analyzing the correlation of the semi-orthogonal filter banks are proposed. The integer translates of the wavelet and scaling function are nearly-orthogonal. The integer translates of the wavelet at different scale are completely orthogonal. The semi-orthogonal filter bank can be efficiently implemented using the corresponding nearly-orthogonal FIR filter bank.     

Multiresolution Bilateral Filtering for Image Denoising

The bilateral filter is a nonlinear filter that does spatial averaging without smoothing edges; it has shown to be an effective image denoising technique. An important issue with the application of the bilateral filter is the selection of the filter parameters, which affect the results significantly. There are two main contributions of this paper. The first contribution is an empirical study of the optimal bilateral filter parameter selection in image denoising applications. The second contribution is an extension of the bilateral filter: multiresolution bilateral filter, where bilateral filtering is applied to the approximation (low-frequency) subbands of a signal decomposed using a wavelet filter bank. The multiresolution bilateral filter is combined with wavelet thresholding to form a new image denoising framework, which turns out to be very effective in eliminating noise in real noisy images. Experimental results with both simulated and real data are provided.      

一种双模波导滤波器及应用

基于波导谐振器模式分析理论,文中介绍了一种TM 双模波导谐振器,并采用该谐振器仿真设计了微波滤波器。该滤波器具有体积小、Q 值高、便于调试安装等特点。 滤波器谐振器采用了 TM120 及 TM210 双模设计,谐振器尺寸可以灵活设计,适用于多种需求。 文中采用电磁仿真软件进行了滤波器的设计及优化,并分析了多种物理结构,包括同轴结构输入输出滤波器、高阶滤波器及腔体谐振器平面排列结构的滤波器。 生产加工了一台 Ku 频段的滤波器,测试性能优良,测试数据和仿真数据一致性好。     

Deterministic and statistical properties of two-dimensional FIR-median hybrid filters

In this paper, we present a new class of two-dimensional FIR-median hybrid (FMH) filters, which we call separable FMH filters, for image noise smoothing. In a separable FMH filter, a one-dimensional FMH filter is applied to the rows and the columns of an image successively. The deterministic properties of separable and cross window FMH filters are discussed. Under certain assumptions, it is proved that a root of a separable FMH filter is a root of the corresponding cross window FMH filter. The noise attenuating properties of a separable FMH filter are studied and compared with those of the separable median filter, the two-dimensional median filter with a square window, and the cross window FMH filter.     

太赫兹光子滤波器技术的研究

太赫兹技术具有分辨率高、穿透力能力强等优点,正逐步成为军事和民用领域的研究热点。介绍了工作于太赫兹波段的光子滤波器的工作原理,推导了光子滤波器的传递函数,在此基础上设计了一种新型的基于级联调制器的光子滤波器结构,利用Optisystem构建了传统光子滤波器和级联调制器的光子滤波器的仿真模型,并进行了对比仿真和分析。研究发现滤波器的品质因数Q和掺铒光纤放大器的最大输出功率有直接关系,基于级联调制器的光子滤波器具有更好的滤波特性。     

Complex notch filter design using allpass filter

Complex coefficient IIR notch filter design problems are investigated. The specification of a notch filter is first transformed into that of an allpass filter. An effective approach to the design of this desired allpass filter is developed. The realisation of the proposed notch filter is equivalent to the realisation of an allpass filter. Owing to the mirror-image symmetry relation between the numerator and denominator polynomials of allpass filters, the notch filter can be realised by a computationally efficient lattice structure with very low sensitivity     

On the design of FIR analysis-synthesis filter banks with highcomputational efficiency

Presents an effective design algorithm for analysis-synthesis filter banks with computationally efficient structures. Although a wide variety of implementation structures can be accommodated, the focus of the paper is on cosine modulated filter banks. The design procedure is based on a time domain formulation of analysis-synthesis filter banks in which each individual channel filter is constrained to be a cosine modulated versions of a baseband filter. The resulting filter banks are very efficient in terms of computational requirements and are relatively easy to design. A unique feature of this approach is that relatively low reconstruction delays can be imposed on the system. A discussion of the associated computational properties of the designed systems and some design examples are included     

Design of active transimpedance band-pass filters with different Q values

Transimpedance filter is a filter which realises a transimpedance transfer function. In this article, the design methods for the transimpedance band-pass filter are presented. The circuit topologies and parameter calculation formulas of three bi-quadratic transimpedance band-pass filter topologies with low-, medium- and high-Q values are proposed, respectively. A high-order transimpedance filter can be obtained by realising a bi-quadratic transimpedance filter first and then cascaded with voltage-mode bi-quads. A high-order transimpedance filter design example is given; the simulation and the measured results verify the effectiveness of the proposed transimpedance filter design method.     

Design of active transimpedance band-pass filters with different Q values

Transimpedance filter is a filter which realises a transimpedance transfer function. In this paper, the design methods for transimpedance band-pass filter are presented. The circuit topologies and parameter calculation formulas of three bi-quadratic transimpedance band-pass filter topologies with LQ, MQ and HQ are proposed respectively. High order transimpedance filter can be obtained by realising a bi-quadratic transimpedance filter first and then cascaded with voltage mode bi-quads. A high order transimpedance filter design example is given, the simulation and the measured results verify the effectiveness of the proposed transimpedance filter design method.     

一种220 GHz滤波器的设计

基于电感膜片矩形波导滤波器设计方法和加工流程,设计了一个220 GHz带通滤波器。滤波器采用玻璃片—硅片—陶瓷片结构,由硅片形成电感膜片结构,玻璃片、陶瓷片键合在硅片上形成闭合的谐振腔,采用集成电路的制作工艺,在加工前分析了工艺特性,优化了滤波器尺寸,避免工艺对滤波器关键尺寸的影响。采用信号源、功率计进行测试,测试结果表明,滤波器在220 GHz具有通带特性,带内损耗约为7 dB。