一种新型双环双模带通滤波器

本文提出了一种由一个环形谐振器和一个微扰小环构成的新型双环双模带通滤波器。微扰小环具有两个可调参数,增加了调整双模的自由度,从而更容易地调节双模,便于实现滤波器的小型化。抽头输入输出耦合结构可以方便地调整双模滤波器的两个传输零点,从而改善滤波器的通带特性。最后实现了中心频率为2.41GHz,相对带宽为17.77%的双环双模带通滤波器,通带内插入损耗为0.67dB,回波损耗为17dB,且带外衰减大于20dB。     

基于奇偶模分析法的四模谐振器结构的双通带带通滤波器设计

提出了一款基于四模谐振器的新型双通带带通滤波器.设计的四模谐振器基于微带线结构,由四个开路枝节和一个短路枝节组成.两次采用奇偶模分析法对该四模谐振器结构进行分析.该四模谐振器的每个模式能够实现独立调节,同时每两个模式形成一个通带.采用源与负载耦合的馈电方式,提高滤波器的带外抑制性.该滤波器具有四个传输零点和四个传输极点.测试结果表明,该双模双通带滤波器工作于2.08GHz和6.07GHz,3dB带宽分别为11.06%和7.74%.设计的滤波器具有紧凑的结构,只有0.28λ_g×0.11λ_g大小.     

横向双模双频滤波器设计

基于横向滤波器耦合结构,采用支节加载双模谐振器,设计了中心频率位于1.57 GHz(GPS应用)与2.4GHz(WLAN应用)的双频微带滤波器。由短路支节加载双模谐振器形成第一个通带,开路支节加载双模谐振器形成第二个通带,两个谐振器被输入/输出馈线隔离,每个通带的中心频率与带宽可以单独调节。测试结果表明:两个通带内的最小插损分别为2.18,1.35 dB,3 dB带宽分别为5.2%,6.8%,回波损耗均小于16 dB,三个传输零点分别位于1.28,2.08,2.71 GHz处。该滤波器具有尺寸小、带外选择性好等优点。     

新型的平面双模椭圆函数带通滤波器

根据传统的方形贴片双模滤波器,提出了一种新颖的带有两个切角的平面双模带通滤波器结构.该结构使用单个贴片谐振器并且没有耦合缝隙,通带两端各有一个衰减极点,有效减小了滤波器的辐射损耗.对该滤波器结构进行改进,又提出了一种带有两个相互正交、长度不等槽线的双模椭圆函数带通滤波器结构.该滤波器在中心频率1.8GHz处,回波损耗达到31.53 dB,通带内最小插损达到0.01 dB,3 dB相对带宽为19.44%.采用Ansotf公司的En-sem ble 8.0仿真软件进行的仿真研究.仿真结果表明该结构可以更加有效地减小辐射损耗,增加带宽,且体积比传统滤波器减小了约40%,有利于小型化.     

采用电容耦合式馈线的高温超导滤波器设计

为了获得结构紧凑的滤波器,在设计中采用了螺旋形谐振器和电容耦合式馈线结构.利用集总元件等效电路给出了谐振器与电容耦合式馈线组成的电路的谐振频率和有载Q值的表达式.提出了馈线为电容耦合式时的集总元件带通滤波器等效电路.并基于上述电路在MgO基片上设计和实际制作了一个高性能的高温超导微带线滤波器.该滤波器的中心频率为2542 MHz,相对带宽为0.6%,尺寸仅为10mm×15mm.测试结果表明滤波器的带内插损小于0.1 dB,反射损耗为40.0 dB,验证了该等效电路设计方法的有效性.     

应用于北斗L、S频点的新型双频滤波器设计

提出了一种应用于北斗短报文波段（即L和S频点）的背靠背E形双频滤波器设计。该滤波器由两对公共馈电的背靠背E形谐振器并联组成,上方为背靠背E形的微带阶跃阻抗谐振器,下方为背靠背E形的缺陷阶跃阻抗谐振器。通过等效阻抗分析、表面电流仿真、参数优化得到滤波器的结构,滤波器尺寸为34 mm×21 mm×0.762 mm。实测结果表明,该滤波器的两个中心频点分别为1.62 GHz和2.53 GHz,相对带宽分别为8%和3%,带内插入损耗均小于2.2 dB,回波损耗均大于11.8 dB,相邻通带间的隔离度大于15 dB。测试结果与仿真结果基本吻合。     

一种利用环形双模谐振器实现的带阻滤波器

提出了一种利用双模环形谐振器实现的带阻滤波器。该滤波器由一个对称的双模环形谐振器以及一段四分之一波长的平行耦合线组成。借助于在普通环形谐振器的两个相对边上添加一对小贴片,环形谐振器的两个简并谐振模式可以被可控的分离,从而可以构成带阻滤波器的工作频带。平行耦合线的作用是为了对双模谐振器进行馈电,同时也被用做两端口间的阻抗变换器。在理论分析之后,利用平面PCB工艺设计制作了滤波器样品,并对其进行了测量,进一步证明这种设计的有效性。     

具有小中心频率比的紧凑型双频带滤波器

采用平面双模谐振器设计了一款新颖的具有小中心频率比的紧凑型双频带滤波器。该滤波器的两个工作频段的中心频率分别为5G WiFi的两个有用频段5.2 GHz和5.8 GHz,中心频率比为1:1.1。实现了具有四个传输零点的双通带响应,其中位于两个频带中间的两个传输零点由谐振器自身产生,很好地抑制了通带间的无用频段。另外两个传输零点由源负载耦合结构产生。加工并测试了该滤波器,两个通带的3 dB相对带宽为5.8%和5.2%,通带内的插入损耗小于0.8 dB,四个传输零点分别位4.52, 5.50,5.50和6.50 GHz,实验和仿真结果吻合,验证了结构的有效性。     

基于T 型谐振器的新型可重构滤波器的设计

基于T 型谐振器结构,设计了一款新型小型化可重构滤波器。它可以通过开/ 关射频开关,实现三种滤波器的重新配置。这三种模式分别为带阻滤波器(BSF)、宽阻带带阻滤波器(WB鄄BSF)和双模带通滤波器(DB-BPF)。设计并制造了一款小型可重构滤波器实物(εr =2.65,h =1 mm)。其中,带阻滤波器的阻带中心频率为3.89 GHz,-3 dB相对带宽为90.9% (2.12 - 5.65 GHz);宽带带阻滤波器的阻带中心频率为3.54 GHz,-3 dB 相对带宽为137.85%(1.1～5.98 GHz);双模带通滤波器的两个通带中心频率分别为1.53 GHz 和6.89 GHz,-3 dB 相对带宽分别为17. 6%(1.4～1.67 GHz)和1.16% (6.85～6.93 GHz),两通带之间回波损耗优于15 dB。实物测试结果与仿真结果基本一致。     

厘米波段介质带通滤波器的设计与制作

为了提高基站的通信质量,研制了高性能的窄带介质带通滤波器。选择切比雪夫低通原型设计线路,采用6个环形介质谐振器直接耦合实现滤波器,输入输出采用探针耦合。用HFSS软件对滤波器的结构进行了仿真。用εr=38的高Q值介质陶瓷材料制作了环形谐振器,分析了衬垫材料的高度对环形谐振器性能的影响,测试了级间耦合系数。最后制作出中心频率为6GHz的介质带通滤波器,滤波器的带宽窄（0.5%）,插入损耗较小,阻带衰减很高,达到了国内先进水平。     

Current-mode continuous-time filters using complementary current mirror pairs

A design of current-mode continuous-time filters for low voltage and high frequency applications using complementary bipolar current mirror pairs is presented. The proposed current-mode filters consist of simple bipolar current mirrors and capacitors and are quite suitable for monolithic integration. Since the filters are based on the integrator type of realization, the proposed method can be used for a wide range of applications. The frequency of the filters can easily be changed by the DC controlling current. A fifth-order Butterworth and a third-order leapfrog filter with tunable cutoff frequencies from 20 MHz to 100 MHz are designed as examples and simulated by SPICE using standard bipolar parameters.     

Inverse Ultraspherical Filters

The inverse ultraspherical filter is derived and its properties analyzed. It is shown that the inverse ultraspherical filter has smaller transition band than the inverse Chebyshev filter under certain circumstances while still maintaining the maximally flat passband characteristic. Filter pole and zero calculations are described and typical magnitude and delay responses generated. Nomographs of inverse ultraspherical filters are also provided for determining filter order and for possible magnitude response optimization.Celestino A. Corral was born in Havana, Cuba. He earned his Bachelors, Masters and Ph.D. degrees in electrical engineering from the University of Miami, Florida, in 1985, 1987, and 1993, respectively. He completed his Ph.D. program under a Patricia Roberts Harris fellowship. From 1988 to 1990 Dr. Corral was a Member of the Technical Staff at Sandia National Laboratories, Albuquerque, New Mexico, where he was involved in the analysis, modeling, and design of custom circuits for piezoelectric sensor components. In 1994, he joined Scientific-Atlanta in Atlanta, Georgia, as an Associate Staff RF Engineer and worked on communication systems and specialized microwave software. In 1997 he was Senior Design Engineer at Origin Data Systems in Boca Raton, Florida, where he had multiple roles in system, hardware, and software development for a novel asset management/RFID system. Currently, Dr. Corral is a Distinguished Member of the Technical Staff in Motorola Labs, Plantation, Florida, and is involved in ultra-wideband, wideband, and propagation research. His interests include circuit and filter theory, communication systems, numerical analysis, signal processing, and constrained optimization. He has published over twenty-five journal and conference papers, has six patents filed, and two trade secrets.Dr. Corral was principal recipient of the Myril B. Reed Best Paper Award for the 40th Midwest Symposium on Circuits and Systems in 1997. Dr. Corral is also the principal recipient of the Ambrose Fleming Premium for IEE Proceedings on Circuits, Devices, and Systems, 2000. Dr. Corral is a Senior Member of IEEE and a member of Omicron Delta Kappa, Tau Beta Pi, and Eta Kappa Nu honor societies.     

波导带通滤波器的精确设计和快速优化

介绍了采用三维微波电磁场仿真软件快速提取直接耦合波导带通滤波器耦合窗口参数的方法,并提出了优化最终模型的快速扫描技术.全波仿真及实验结果表明,该方法能满足波导带通滤波器快速精确设计的要求.     

Design of two-dimensional directional filters

A directional filter has a passband extending fully along a straight line passing through the origin. In its original form the transformation technique, a powerful tool for designing two-dimensional FIR filters, is not useful to design such a filter. In this communication we suggest a few analytical and optimisation-based methods to design directional filters using the transformation technique. The superiority of the proposed methods over existing techniques is demonstrated.     

一种基于CIC滤波器的有效锐化方法研究

介绍了对积分梳状滤波器（CIC滤波器）的有效锐化。所提出的锐化滤波器的结构由两个主要部分组成：一个梳状滤波器的级联部分和一个锐化滤波器部分。所提出的方案使得滤波器中锐化部分的工作速率比输入速率大为降低，其频谱响应特性比传统的也有所改进。通过MATLAB仿真，可看出改进锐化后的滤波器性能更优。     

Miniaturized dielectric waveguide filters

Design techniques for a new class of integrated monolithic high-permittivity ceramic waveguide filters are presented. These filters enable a size reduction of 50% compared to air-filled transverse electromagnetic filters with the same unloaded Q-factor. Designs for Chebyshev and asymmetric generalised Chebyshev filter and a diplexer are presented with experimental results for an 1800 MHz Chebyshev filter and a 1700 MHz generalised Chebyshev filter showing excellent agreement with theory.     

DDC中的抽取滤波器设计及FPGA实现

本文介绍了在数字下变频（DDC）中的抽取滤波器系统设计方法和具体实现方案。采用CIC滤波器、HB滤波器、FIR滤波器三级级联的方式来降低采样率。通过实际验证，证明了设计的可行性。     

一种数字下变频抽取滤波器的设计

对一个针对数字下变频应用的抽取滤波器从设计指标到版图实现的设计过程进行了详细介绍.该抽取滤波器实现了20倍的降采样,由CIC滤波器、CIC补偿滤波器和半带滤波器三级依次串联而成.通过利用抽取滤波器的等价变换和多项分解性质,各滤波器级的硬件电路开销和运行功耗都得到了降低.     

大功率谐波吸收式滤波器设计

介绍了大功率谐波吸收式滤波器的实现电路，这些电路满足了信号分流的技术要求。文中给出了详细的工作原理和测试数据。     

Single-stage line-coupled ac/dc converter with high power factor and ripple-free input current

Single-stage line-coupled ac/dc converter with high power factor and ripple-free input current is proposed. The proposed power factor correction circuit can achieve high power factor and ripple-free input current using a coupled inductor. Experimental results for a 400?W converter at a constant switching frequency of 100?kHz are obtained to show the performance of the proposed converter.