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滤波器特性的非等波纹逼近方法 总被引:1,自引:0,他引:1
本文提出滤波器特性的非等波纹逼近方法。利用切比雪夫多项式构成有理函数,并与频率相关的系数组成特征函数,从而获得接近于同阶数椭圆函数滤波器的衰减特性,明显优于切比雪夫和逆切雪夫滤波器。理论明晰,过程简单,便于计算机编程。非等波纹逼近方法是最平坦逼近和等波纹逼近的一种中间形式,有其实用价值。 相似文献
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针对传统脊波导滤波器设计中没有考虑耦合结构频率特性导致设计精度不高的问题,文中提出了一种基于消失模耦合的脊波导滤波器设计方法。该方法将工作于消失模状态下的矩形波导结构等效为频变阻抗变换器模型,通过等效电路变换将耦合结构的频变特性影响转换为对传输线谐振腔电抗斜率参数的影响,采用逐级仿真策略确定滤波器结构尺寸,避免了耗时的全波仿真优化。最后,通过一个4阶切比雪夫特性的脊波导滤波器设计实例进行验证。全波仿真结果显示了与理论设计相同的通带内等波纹特性,验证了所提方法的有效性。 相似文献
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文中提出一种基于缺陷地结构的新型低通滤波器。其由位于微带结构顶部的加宽微带线、位于接地层中的经典哑铃型缺陷地结构(DGS)和蛇形缝隙缺陷地结构(DGS)组成,结构设计紧凑,容易调整。文中选用0.01 dB等波纹的切比雪夫型低通滤波器,分别采用哑铃型DGS、蛇形缝隙DGS替换LPF原型电路中的电感,加宽微带线替换并联电容,同时将加宽微带线产生的寄生电感考虑进去。哑铃型DGS产生的高频衰减点加宽阻带,蛇形缝隙DGS提供的低频衰减点使得通带到阻带陡峭过渡。实验结果表明,所设计的截止频率为2.54 GHz的低通滤波器具有明显的截止频率响应,通带内插损均在0.9dB以下,阻带抑制均在21dB以下。经实物加工测试验证,所设计的低通滤波器实际结果与仿真结果基本一致,具有可行性。 相似文献
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Often in infinite impulse response (IIR) filter design, our critical design parameter is the cutoff frequency at which the filter's power decays to half (-3 dB) the nominal passband value. This article presents techniques that aid in the design of discrete-time Chebyshev and elliptic filters given a 3-dB attenuation frequency point. These techniques place Chebyshev and elliptic filters on the same footing as Butterworth filters, which traditionally have been designed for a given 3-dB point. The result is that it is easy to replace a Butterworth design with either a Chebyshev or an elliptic filter of the same order and obtain a steeper rolloff at the expense of some ripple in the passband and/or stopband of the filter. 相似文献
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基于基片集成波导(substrate integrated waveguide,SIW)结构设计了两款四阶的耦合带通滤波器,使用三维全波电磁场仿真软件HFSS对设计的两款滤波器进行了仿真设计和优化.由仿真结果分析得出,两款滤波器的工作频率均位于毫米波频段.第一款SIW滤波器实现了切比雪夫型响应,中心频率为20 GHz,带宽为2 GHz,通带内的插入损耗低于1.5 dB,回波损耗低于-20 dB,在阻带中对信号的衰减程度可以达到50 dB.第二款SIW滤波器实现了准椭圆函数型的响应,中心频率为29.1 GHz,带宽为300 MHz,通带内的插入损耗低于1 dB,回波损耗低于-20 dB,在通带到阻带的过渡中实现了两个陷波点.仿真结果表明,在毫米波滤波器设计中引入SIW结构,有利于优化滤波器尺寸,得到较好的滤波器性能指标,是毫米波滤波器发展的一个重要方向. 相似文献
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《Microwave Theory and Techniques》1980,28(8):865-874
The transmission characteristics and a design method are presented for a transmission-line Iow-pass filter with multiple pairs of coincident zeros in the finite frequency of the passband and multiple pairs of coincident poles in the finite frequency of the stopband and for a transmision-line low-pass filter with Butterworth characteristic in the passband and multiple pairs of coincident poles in the finite frequeney of the stopband. The former transmission-line low-pass filter shows an improved skirt attenuation performance and delay characteristic than a Chebyshev transmission-line low-pass filter in the same network degree. The latter type of transmission-line low-pass filter shows an improved skirt attenuation performance in comparison to a Butterworth transmission-line low-pass filter in the same network degree, it is positioned about in the middle between a Butterworth type and a Chebyshev type, the delay characteristic is improved considerably in comparison to the Chebyshev type, and the characteristic is close to that of the Butterworth type. With this design method, the connecting unit elements in addition to the stubs contribute to the attenuation response. The design example is shown on the basis of a concrete specification, and it is shown that the obtained attenuation strictly fulfills the specification. 相似文献
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An analog baseband circuit made in a 0.35-μm SiGe BiCMOS process is presented for China Multimedia Mobile Broadcasting (CMMB) direct conversion receivers. A high linearity 8th-order Chebyshev low pass filter (LPF) with accurate calibration system is used. Measurement results show that the filter provides 0.5-dB passband ripple, 4% bandwidth accuracy, and -35-dB attenuation at 6 MHz with a cutoff frequency of 4 MHz. The current steering type variable gain amplifier (VGA) achieves more than 40-dB gain range with excellent temperature compensation. This tuner baseband achieves an OIP3 of 25.5 dBm, dissipates 16.4 mA under a 2.8-V supply and occupies 1.1 mm2 of die size. 相似文献
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A 1-V +31 dBm IIP3, Reconfigurable, Continuously Tunable, Power-Adjustable Active-RC LPF 总被引:1,自引:0,他引:1
Amir-Aslanzadeh H. Pankratz E.J. Sanchez-Sinencio E. 《Solid-State Circuits, IEEE Journal of》2009,44(2):495-508
This paper proposes a biquad design methodology and presents a baseband low-pass filter for wireless and wireline applications with reconfigurable frequency response (Chebyshev/Inverse Chebyshev), selectable order (1st/3rd/5th), continuously tunable cutoff frequency (1-20 MHz), and adjustable power consumption (3-7.5 mW). A discrete capacitor array coarsely tunes the low-pass filter, and a novel continuous impedance multiplier (CIM) then finely tunes the filter. Resistive/capacitive networks select between the Chebyshev and inverse Chebyshev approximation types. Also, a new stability metric for biquads, minimum acceptable phase margin (MAPM), is presented and discussed in the context of filter compensation and passband ripple considerations. Experimental results yield an IIP3 of 31.3 dBm, a THD of -40 dB at 447 mVpk, diff input signal amplitude, and a DR of 71.4 dB. The filter's tunable range covers frequencies from 1 MHz to 20 MHz. In Inverse Chebyshev mode, the filter achieves a passband group delay variation less than plusmn2.5%. The design is fabricated in 0.13 mum CMOS, occupies 1.53 mm2 , and operates from a 1-V supply. 相似文献
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This paper proposes a new current-mode 5th-order differential type class-AB log-domain elliptic lowpass filter for video frequency
applications. The design is based on the state-space synthesis method. The proposed filter has 5.75 MHz cut-off frequency
with maximum 0.177 dB passband ripple and attenuation greater than 40 dB at 7.88 MHz. Only BJTs and grounded capacitors were
used, and operated with single power supply of 2.5 V. Since the parameters of proposed filter are tunable, it is easy to control
of cut-off frequency. This adjustment is accomplished by changing external currents. SPICE simulations are given to confirm
the theoretical analysis. For this purpose, the filter is simulated by using both idealized BJT models and AT&T CBIC-U2 type
transistors. 相似文献
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采用0.18μmCMOS工艺设计了一款应用在无线传网中的三阶级联有源RC复数带通滤波器,同时设计了自动频率调谐电路(AFT)。该滤波器采用的是切比雪夫逼近函数予以实现。在5比特数字控制码开关电容阵列的控制下,AFT电路即可完成对主体滤波器电路频率变化的校正。仿真结果显示,滤波器的中心频率稳定在2MHz,通带带宽为2MHz,镜像抑制比大于34dB,相邻信道阻带衰减大于34dB,通带纹波小于1dB,消耗电流为2.3mA,工作电源电压为1.8V。 相似文献
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IIR数字滤波器的Matlab和FPGA实现 总被引:1,自引:0,他引:1
提出一种通过两个二阶节级联构成四阶IIR数字椭圆滤波器的设计方法,并利用Matlab仿真软件设计了通带内波纹不大于0.1 dB,阻带衰减不小于42 dB的IIR数字滤波器。论述了一种采用可编程逻辑器件,通过VHDL硬件描述语言实现该滤波器的方法。给出了在QuartusⅡ软件下的仿真结果,并在FPGA器件上验证实现。实验证明,这种方法是切实可行的。 相似文献