广义Chebyshev最优滤波器设计

本文论证了等波纹广义Chebyshev函数滤波器的最优化特性,提出了由设计指标得到广义Chebyshev函数的方法,并且引入信号流图非常简便的得到了对应网络的拓扑结构,最终完成滤波器的设计.本文对具有带外传输零点的滤波器设计具有相当重要的意义.     

广义Chebyshev最优滤波器设计

本文论证了等波纹广义Chebyshev函数滤波器的最优化特性，提出了由设计指标得到广义Chebyshev函数的方法，并且引入信号流图非常简便的得到了对应网络的拓扑结构，最终完成滤波器的设计．本文对具有带外传输零点的滤波器设计具有相当重要的意义．     

基于传输零点的广义切比雪夫型LC滤波器快速设计法

通过对不同结构的广义切比雪夫型LC滤波器的传输零点特性进行分析验证,得到适用于N阶广义切比雪夫型LC滤波器传输零点特性的结论。基于这些结论提出一种快速设计广义切比雪夫型LC滤波器的方法,大大缩短了设计滤波器的时间。并且该方法可以在实现滤波器带外截止特性的同时,实现滤波器小型化,在科学研究和工程应用中具有重要意义。     

广义切比雪夫型LC滤波器的设计*

提出一种广义切比雪夫型LC滤波器的设计方法,带外传输零点可以是任意设定,其带外特性既可以对称,也可以不对称.采用此方法设计出的LC滤波器,其带内波动可以与最大平坦型滤波器一样很小,而矩形系数可以与椭圆函数型滤波器一样好.每一个传输零点的位置可以由一个元器件的取值大小控制.与椭圆函数型LC滤波器相比,相同数量的元器件,它可以实现更陡的截止特性.     

基于多层技术双通带Chebyshev滤波器综合设计

为了提高滤波器的选择性,实现小型化,采用多层板技术综合方法设计了一款双通带Chebyshev响应带通滤波器.利用组成上通带的半波长开环谐振器的空间交叉耦合引入两个有限频率传输零点,以提高滤波器频率选择性.同时,利用组成下通带的四分之一波长短路谐振器形成零度馈电混合耦合结构,生成另外两个传输零点,不但提高了通带隔离度,而...     

广义切比雪夫滤波器等效电路参数的提取

通过对等效电路的分析,对广义切比雪夫滤波器各归一化参数的物理意义做了明确的说明,并且,在指定传输零点位置和电路拓扑结构的情况下,采用优化方法,提出了一种灵活有效的提取广义切比雪夫滤波器等效电路参数的方法。最后,用MATLAB编程实现了等效电路参数的自动化提取。     

四阶交叉耦合广义切比雪夫带通滤波器的设计

利用Matlab和HFSS设计了一个四阶交叉耦合广义切比雪夫滤波器,文中详细介绍了设计步骤,设计出的滤波器中心频率为2.60GHz,通带内的回波损耗为15dB,通带相对带宽FBW=6%,传输零点位置在2.485GHz和2.72GHz。     

X波段发卡式带通滤波器设计

采用引入传输零点的方法设计了一款发卡式带通滤波器。该滤波器由5个发卡单元构成,中心频率为8.6GHz.。通过在第2和第4个发卡谐振器上并联微带开路线的方法引入传输零点,来实现更好的边带抑制。通过调节并联微带线的长度来控制传输零点的位置,实现对边带抑制效果的有效控制。     

枝节加载的双模微带滤波器设计

为了实现滤波器的小型化和高性能,研究了中心枝节加载的E型双模谐振器的谐振模式与传输零点的产生机理,发现可以通过控制奇偶模的频率关系来设置传输零点的位置。基于此分析设计了几款不同的带通滤波器来验证该结论,通过引入合适位置处的传输零点设计制作了结构紧凑、频率选择性好、带外抑制能力强的双工器和双模双通带滤波器。结果表明通带外的零点测量位置和仿真结果基本吻合,该方法能够应用到微波电路的设计中。     

新型传输零点可控的共面波导带通滤波器

提出了一种新型传输零点可控的共面波导(CPW)结构双模带通滤波器.该滤波器采用了新型的"王"字形共面波导谐振腔."王"字形共面波导谐振腔是由一段均匀阻抗线和两侧与之相连的"T"形枝节构成.调节谐振腔上下"T"形枝节的长度,可以改变谐振器的两个谐振模式之间的距离,从而灵活的调节了滤波器的带宽.调节"T"形枝节的长度还可以控制滤波器传输零点的位置,从而增强带外抑制.仿真与实测结果都表明该滤波器具有良好的性能:低插损,结构紧凑,易于加工制作,可以灵活的调节带宽和传输零点的位置.     

基于遗传算法与单纯形下山法的广义切比雪夫滤波器的优化设计

广义切比雪夫滤波器是一种高性能滤波器形式,用经典的综合方法提取其参数复杂且难以实现。本文以指定的电路拓扑结构和传输零点作为已知条件,结合遗传算法和单纯形下山法用MATLAB编程实现了一种新的灵活、有效的广义切比雪夫滤波器等效电路参数的优化提取方法。并给出了归一化耦合系数的物理意义及其工程应用系数转换公式。     

应用于新能源发电系统的双输入高增益直流变换器

在新能源联合发电系统中,多输入直流变换器能够简化系统结构和降低成本,因而被广泛采用。针对现有的多输入直流变换器输出电压低、功率不稳定的问题,提出了一种新型双输入高增益直流变换器拓扑。从双输入直流变换器的工作原理出发分析变换器的工作特性,并计算在不同工作方式下的电压增益。不同模式下的MATLAB/Simulink仿真结果表明,该电路拓扑具有高升压比、电路拓扑简洁,且输入源可根据负载协调分配等优点。     

Transmission Characteristics and a Design Method of Transmission-Line Low-Pass Filters with Multiple Pairs of Coincident Zeros and Multiple Pairs of Coincident Poles

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.     

Narrow-Band Stripline or Microstrip Filters with Transmission Zeros at Real and Imaginary Frequencies

Simple approximate design equations are derived in this paper for an even degree (n /spl ges/ 6) low-pass inverter capacitance prototype filter having single transmission zeros at both real and imaginary frecuencies. This is achieved by utilizing one or two additional couplings. The transmission zeros improve considerably the passband group delay and increase the skirt selectivity compared to those of the ordinary Chebyshev prototype. An exact and more complicated method based on the known generalized Chebyshev rational function approximation is also presented for the comparison. The prototype with one additional coupling is utilized to realize narrow-bandpass printed circuit filters consisting of half-wave resonators.     

Microstrip Parallel-Coupled Filters With Cascade Trisection and Quadruplet Responses

Microstrip parallel-coupled filters with generalized Chebyshev responses are presented. The basic structure of the proposed filter is a conventional parallel-coupled filter of which the physical dimensions can be easily obtained by the well-known analytical method. With the aid of the equivalent circuit corresponding to a conventional parallel-coupled filter, the relative insertion phase from source or load to each open end of resonators can be easily obtained by observing the two-port admittance matrix. Applying the cross coupling from source or load to a proper nonadjacent resonator, a trisection or a quadruplet coupling scheme can be realized with prescribed transmission zeros. More importantly, the proposed trisection can be designed to have a transmission zero on the lower or upper stopband by just adjusting the length of the cross-coupling strip. Using the proposed structure, the conventional time-consuming adjusting procedure to obtain initial physical dimensions of filters is no longer required. In this paper, a fourth-order parallel-coupled filter is used as the basic structure to demonstrate various combinations of transmission zeros. Simulated and measured results are well matched.      

Serially-connected series-stub resonators for narrowband coplanar-stripline bandpass filters

In this letter, a coplanar stripline (CPS) series resonator composed of serially-connected series-stubs is proposed. This kind of resonator provides two transmission zeros close to the resonant frequency. With the proposed structure, the reactance slope parameters of the resonators are significantly increased and adjustable by changing the length ratio of the two series stubs. This is useful for designing narrowband filters which is difficult to realize with conventional series CPS resonators. The structures of the resonators are optimized for a lower radiation loss and used to design a narrowband Chebyshev bandpass filter. The simulation and experimental results show that the proposed filter provides multiple transmission zeros and high selectivity.     

一种X波段同轴双工器设计

在具有有限传输零点的广义Chebyshev带通滤波器的综合理论基础上,根据计算出的耦合矩阵设计滤波器仿真模型,应用电磁仿真软件结合最优化方法,采用群时延拟合法对双工器的尺寸进行优化设计.实物测试结果表明,双工器的插入损耗≤1.5 dB,输入输出电压驻波比≤1.5,带外抑制大于85 dB,得到的实测曲线满足设计要求,论证了该方法的正确性.