偶数阶电流模椭圆滤波器的综合设计

本文提出了一种基于MOCCII的任意偶数阶电流模椭圆滤波器综合设计方法。通过对n阶(偶数)椭圆传输函数进行分析,将其分解成一系列能用无损积分器实现的表达式;并对输出电流信号进行线性组合,以实现了偶数阶的电流模式椭圆滤波器的综合。该方法实现的电路结构简单,所用有源和无源元件最少,仅由n个接地电容,(3n-1)/2个有源器件和接地电阻构成。给出了四阶高通、低通和带通椭圆形滤波器的设计实例。Pspice仿真结果表明采用该方法设计偶数阶电流模式椭圆滤波器是可行的,适用的。     

双线性变换一阶及二阶开关电容电路设计

按双线性变换方法构成的一阶及二阶开关电容电路不但可以用来构成所有各种类型的级联滤波器,而且在按照模拟低通原型滤波器构成的跳耦电路中,用适当的二阶开关电容电路代替积分电路,可将原型滤波器变换为带通或带阻滤波器。文中给出了一阶及二阶开关电容电路的系统设计方法,讨论了各类电路的灵敏度及如何调整电路参数以获得最大输出动态范围。     

多环反馈开关电容滤波器结构

本文介绍一种新的开关电容滤波器设计技术。所提出的技术是基于用多环反馈结构来实现对寄生电容不敏感的一阶开关电容滤波器结构单元。用这种方式得到的开关电容滤波器对于顶板和底板寄生电容不敏感,能够实现任何稳定的N阶离散时间传递函数。设计了一个带通滤波器作为例子,其灵敏性能通过蒙特卡罗分析法加以说明。     

开关电容滤波器的设计

本文简要阐述了基本开关电容工作原理,介绍了两种开关电容滤波器的设计方法,并用其进行ＤＴＭＦ滤波器中低通、带通和高通滤波器的设计。     

开关电容滤波器的系统设计与实现

通过合理选择滤波器的类型和阶数,利用低Q值二级滤波器放在高Q值二级滤波器的前级,给每一级分配不同的增益使得每一级的输出峰值相同.从开关电容电路的原理入手,分析了开关电容电路和电容编程阵列,最终设计一个可编程开关电容6阶带通滤波器.选择合适的运算放大器参数.可编程滤波器系统共需3路时钟控制,滤波器编程参数控制模块用于实现芯片内部程序存储器编程控制.通过对设计的开关电容滤波器进行仿真,结果基本与设计目标吻合.     

任意阶OTA-C多功能滤波器的设计。

提出了一种新的任意阶运算跨导放大器——电容(OTA-C)多功能滤波器的设计方法。通过将n阶传递函数分解为n+1个一阶传递函数,导出了任意阶传递函数OTA-C实现电路。适当选择各输入端电压,可实现低通、高通、带通、带阻、全通等滤波功能。文中给出了6阶滤波器设计实例,PSPICE仿真结果与理论分析相吻合,验证了设计方法的可行性。     

一种高输入阻抗单CCII电压模式滤波器

提出了一种实现高输入阻抗电压模式滤波器的新电路。该电路使用一个CCII(第二代电流传输器)和最少量的RC元件实现一阶低通、一阶高通及二阶带通滤波器。一阶滤波器仅含3个接地RC元件,二阶滤波器含4个RC元件,其中电容均接地。给出了电路的有源及无源灵敏度及计算机PSPICE仿真结果     

基于Switched-RC技术的0.8V带通滤波器

开关电容滤波器是信号处理系统的重要组成模块,设计了一种用于心率检测设备的六阶带通开关电容滤波器。该设计基于开关电阻电容技术,利用开关电阻代替传统的采样开关,实现了更高的采样线性度,是低压下开关电容滤波器正常工作的一种全新实现方案。仿真结果表明,该滤波器在0.8 V工作电压下,功耗为0.9 mW,输出摆幅可达1.2Vp-p,通带增益为10 dB,-3 dB带宽为25~80 Hz。     

一种高输入阻抗单CCⅡ电压模式滤波器

提出了一种实现高输入阻抗电模式滤波器的新电路。该电路使用一个ＣＣⅡ（第二代电流传输器）和最少量的ＲＣ元件实现一阶低通、一阶高通及二阶带通滤波器。一阶滤波器仅含３个接地ＲＣ元件,二阶滤波器含４个ＲＣ元件,其中电容均接地。给出了电路的有源及无源灵敏度及计算机ＰＳＰＩＣＥ仿真结果。     

基于E型频变负阻的五阶椭圆高通滤波器设计

用电流传送器实现的E型频变负阻、接地电感和浮地电感作为单元电路,提出了实现高阶椭圆高通滤波器的设计方法.用该方法设计的有源滤波电路具有无源梯形网络原型的低灵敏度特性,给出了五阶椭圆高通滤波器的设计例子和PSPICE仿真结果.     

Variable-centre-frequency constant-bandwidth linear-phase digital bandpass filters

A third-order cosine transformation is used to obtain a variable-centre-frequency constant-bandwidth linear-phase digital bandpass filter, the bandwidth being the same as that of the prototype bandpass filter.     

一种用CFA实现的通用高阶滤波器

以信号流图为基础,用CFA设计了一种通用高阶滤波电路。这种电路结构由CFA和电阻、电容组成,具有通用性,只需调整接地阻抗的值,就能实现高阶低通、带通、高通及带阻几种不同的滤波功能。列举了四阶带通和五阶高通两种滤波器,并对两种滤波器进行了仿真,PSpice仿真结果与理论分析一致。     

A design of a simple structure switched-capacitor filter based on the concept of the bilinear transformation

A design procedure of the SCF based on the concept of the bilinear transformation is proposed. The final SCF structure is the same as that obtained by the LDI transformation, which means a structure simpler than the usual SCF obtained by the bilinear transformation and which requires no sample-and-hold circuits at the front and back of it when it is employed with the prefilter and the postfilter as the analog filter. The filter response does not suffer from the effect of the inexact simulation of the terminated resistance of the prototype LC filter which appears in the SCF realization based on the LDI transformation and the aperture effect is compensated. The filter performance realized by the proposed design procedure is tested by an experimental circuit with discrete elements.     

一种适合带通/宽带滤波器的新型电流差放大器

介绍了一种具有双端电流电流输出的电流差大器的新型结构，应用这种电流差放大器，在实现处理电流的一附规范全通滤波器的基础上，导出了新型电流模式高Q值二阶带通滤波器和宽带滤波器。其中，高Q值带通滤波器不受元件匹配条件的约束，调节Q值时不影响中心频率f0。上述电路的PSPICE仿真结果与理论分析相互吻合。     

Synthesis of a Passive Complex Filter Using Transformers

In this paper, the synthesis of a passive complex filter has been described. First, a normalized real coefficient filter is transformed into a complex coefficient filter, which includes imaginary-valued resistors by using a proposed frequency transformation. Second, a complex filter using passive elements is presented. The proposed circuit consists of terminating resistors, capacitors, and transformers with finite self-inductances and coupling coefficients equal to or less than unity. A third-order complex Chebyshev bandpass filter is designed using practical passive elements, and its frequency response is measured. It is shown that the experimental circuit exhibits bandpass characteristics (90–110 kHz) and an image rejection of 53 dB.      

Narrowband bandpass filter exhibiting harmonic suppression

A novel bandpass filter is presented using ring resonators employing corrugated couplers in order to provide suppression of the second harmonic. The filter exhibits a 2.0% bandwidth at a centre frequency of 2.604 GHz and provides a 39 dB suppression of the second harmonic. The constituent resonator is described and an analogous bandpass filter without corrugations is presented for comparison.     

FIR低通和带通滤波器的关系分析与仿真

为了避开直接设计带通滤波器的繁琐设计步骤要求,利用低通滤波器与带通滤波器的关系,间接设计带通滤波器是创新之处,即通过设计简单的低通滤波器从而达到设计带通滤波器的要求。介绍了窗函数法FIR数字低通、带通滤波器的设计,给出了低通滤波器与带通滤波器的频率响应函数,并分析了它们之间的关系,得出了相关结论,结合实例,利用Matlab证实了该结论的正确性,为带通滤波器的设计提供了一种新方法。     

一种新颖微带双通带带通滤波器的设计方法

本文提出了一种新颖的微带双通带带通滤波器的设计方法。该微带双通带滤波器由两个中心频率不同的滤波器组成,并采用耦合线实现外部耦合。设计中引入源与负载之间的耦合,得到了额外的有限频率传输零点,改善了滤波器的衰减特性。通过调节源与负载之间耦合的强弱,可以适当地调节传输零点的位置。经设计并加工了一款4阶微带开环结构双通带滤波器,实测响应与仿真响应吻合较好,验证了该方法的有效性。     

Dual-band bandpass filters using equal-length coupled-serial-shunted lines and Z-transform technique

A synthesizing method is presented to design and implement digital dual-band filters in the microwave frequency range. A dual-band filter consists of a bandstop filter and a wide-band bandpass filter in a cascade connection, wherein the transfer functions of both the bandpass filter and bandstop filter are expressed in the Z domain. The bandstop filter is implemented by using a coupled-serial-shunted line structure, while the wide-band bandpass filter is constructed by using a serial-shunted line configuration. In particular, the bandwidth of each passband of the dual-band filter is controllable by adjusting the characteristics of both the bandpass filter and bandstop filter. By neglecting the dispersion effect between microstrip lines of different widths over a wide bandwidth, a dual-band filter is realized in the form of microstrip lines and its frequency responses are measured to validate this method.     

Bandpass filters using dual-mode and quad-mode Mobius resonators

Compact bandpass filters are being developed using Mobius wire-loaded cavity resonators. Initial results on tuned filters indicate that excellent filter characteristics can be attained in devices that are significantly smaller than traditional wire-loaded cavity technologies. A novel quad-mode Mobius resonator is presented which occupies the same volume as a dual-mode Mobius resonator. A four-pole bandpass filter is demonstrated using a single quad-mode Mobius resonator. Precisely controlled dielectric loading of dual-mode Mobius wire resonators has been implemented to realize bandpass filters. Two-pole and four-pole bandpass filters are demonstrated using one and two dual-mode dielectric-loaded Mobius resonators, respectively