宽阻带阶跃阻抗发夹线带通滤波器设计

提出了新的抑制微带带通滤波器寄生通带的方法。这种方法通过级联阶跃阻抗发夹线谐振器构成的椭圆函数低通滤波器于带通滤波器的输入/输出端,显著改善了后者的阻带抑制特性。本文基于新的等效电路模型,推导出了此类低通滤波器的阻带传输零点位置。设计了L波段宽阻带阶跃阻抗发夹线带通滤波器验证了理论分析和设计过程的正确性。     

基于双二阶的低功耗椭圆带通滤波器设计

为解决椭圆滤波器通带纹波较大的问题,设计了一种基于双二阶的椭圆窄带带通滤波器,滤波器由3个双二阶构造的带阻滤波器级联实现,滤波器中心频率11kHz,带宽2kHz,通带纹波不超过1dB,阻带衰减不小于30dB每倍频程。滤波器功耗不超过30mW,满足水下引信接收机长时间工作的要求。     

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.     

微带SIR带通滤波电路寄生通带的分析

本文分析微带SIR（阶梯阻抗谐振器）带通滤波电路的寄生通带问题。这种滤波器的特点是其寄生响应时以通过阻抗比K进行控制，因而增进了谐波抑制性能。SIR可以采用等电长度或非等电长度。等电长度SIR滤波电路的第三寄生通带的带宽来零，然而，非等电长度SIR滤波电路却增加了设计的灵活性，分析与探讨微带SIR滤波电路的寄生带通问题，对于合理设计与应用这种滤波电路是有益的。     

Coplanar waveguide active bandpass filter

A novel microwave active bandpass filter has been designed in a coplanar waveguide. The approach uses a GaAs FET to link two end-coupled resonators. The realised active filter not only compensates for the losses as compared to a passive filter but also provides an overall gain of 17.54 dB. Flexibility in tuning the filter response through the bias voltage and its superior performance at the harmonics over the passive filters are among the advantages of the design     

Waveguide Bandpass Filters for Millimeter-Wave Radiometers

A fundamental requirement for most mm-wave heterodyne receivers is the rejection of the input image signal which is located close to the local oscillator frequency. For this purpose we use a bandpass filter, which for heterodyne receivers is also called an image rejection filter. In this paper we present a systematic approach to the design of a waveguide bandpass filter with a passband from 100 to 110 GHz and upper rejection bandwidth in the range from 113 to 145 GHz. We consider two non-tunable filter configurations: the first one is relatively selective with 11 sections (poles) whereas the second one is simpler with 5 sections. We used established design equations to propose an initial guess for the geometries of the filters, optimized the geometries, constructed the filters using two different milling methods, measured their transmission and reflection characteristics, and compared the measurements with numerical simulations. Measurements of both filters agree well with simulations in frequency response and rejection bandwidth. The insertion loss of the 11-pole filter is better than 10 dB and that of the 5-pole filter is better than 5 dB. The 11-pole filter has a sharper attenuation roll-off compared with the 5-pole filter. The upper out-of-band rejection is better than 40 dB up to 145 GHz for the 11-pole filter and up to 155 GHz for the 5-pole filter.     

Design concepts for microwave GaAs FET active filters

A comprehensive history of microwave active filter development to date is given. A design methodology is presented for the realization of precision broadband filters in the face of problems such as the nonideal behavior of microwave GaAs FETs and the low Q and related parasitic effects of monolithic-microwave-integrated-circuit (MMIC) inductors and capacitors. The feasibility of this approach is illustrated by the computer-simulated design of a cascadable, second-order microwave bandpass filter     

A novel microstrip square-loop dual-mode bandpass filter with simultaneous size reduction and spurious response suppression

In this paper, a new capacitively stepped-impedance resonator(CSIR) is proposed to develop the microstrip square-loop dual-mode bandpass filter. Using this new design, simultaneous size reduction and spurious response suppression for the dual-mode bandpass filter can be achieved. An analytical formulation of this novel resonator is given in order to elucidate the spurious frequencies relocation design. Together with this formulation, a generalized dual-mode bandpass filter model is developed so as to ease the analysis of transmission zero and insertion loss. A prototype filter is designed at 900MHz with 1.5% fractional bandwidth. Significant spurious suppressions up to 33 and 35 dB are measured at 1.8 and at 2.7 GHz, respectively. A circuitry size reduction of 54% is achieved when compared with that of the conventional structure. Moreover, the CSIR allows frequency tuning and, thus, a varactor-tuned filter is designed and a measured tunable center frequency between 1.5-1.62GHz is demonstrated. Utilizing the proposed structure, not only size reduction,as well as spurious response suppression, but also center frequency tuning can be achieved.     

一种基于DGS结构的新型双模双通带滤波器

提出了一种新颖的基于缺陷地结构(DGS)的双模双通带滤波器.该滤波器由印制板顶面的一个方形谐振单元和另一个巧妙嵌入在印制板底面DGS中的方形谐振单元并联构成,具有结构紧凑、易于加工的特点.每个谐振单元都具有双模单通带传输特性,可通过公共馈线同时激励实现双模双通带滤波.两个谐振单元的谐振频率相对可调,提高了设计上的灵活性.为减少辐射损耗并改善高频通带插损,使用准共面波导缺陷地结构对底面谐振单元进行了改进.最后,实验制作了两种双模双通带滤波器,测试结果与仿真结果吻合较好.     

有源模拟带通滤波器的设计

根据有源模拟带通滤波器的特点,设计了一种工作在低频段且Q值在0～10之间的常用二阶模拟带通滤波器,比较了不同Q值及不同级数级联后的带通滤波器产生的通频带特性,并结合实际电路的效果评价,指出了在设计中应该注意的一些要点.     

Compact bandpass filter based on two meandered parallel-coupled lines in different lengths

A new compact bandpass filter based on two meandered parallel-coupled lines of different lengths in shunt is presented, using the signal-interference technique, this filter obtains a low insertion loss and sharp rejection. A set of analytical formulas and guidelines for the design of the bandpass filter are provided in two theoretical analysis methods. According to the number of attenuation poles of the reflection coefficients in the passband, it can be summed up two types of filters. To validated this topology, two wideband bandpass filters centered at 3 GHz are built to verify the theoretical prediction, the measured frequency response of the filter agrees excellently with the predicted result.     

Systematic Method for the Exact Synthesis of Ultra-Wideband Filtering Responses Using High-Pass and Low-Pass Sections

A systematic consistent and analytical method for the exact synthesis of ultra-wideband bandpass filtering responses using the isolated cascade connection of high- and low-pass sections is presented in this paper. Through the described synthesis technique, the optimum values for the design parameters of the high- and low-pass sections are computed from the initial specifications of the intended bandpass filtering profile. The theoretical results are validated with a synthesis example for both the Butterworth and Chebyshev cases. Furthermore, to prove the practical viability of the ultra-wideband filter topology based on high- and low-pass sections, a prototype at 4 GHz is designed, constructed in hybrid technology, and characterized. The main advantages of this wideband microwave bandpass filter solution are also highlighted.     

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。     

一种新型开路环谐振带通滤波器

利用开路环终端的内部电容耦合效应,提出一种结构紧凑,具有小型化和良好的二阶和三阶谐波抑制能力的开路环谐振器窄带带通滤波器.分析了开路环终端电容内部耦合结构变化对带通滤波器谐波抑制特性的影响,并利用上述结构仿真和设计了一个中心频率为1.5 GHz的带通滤波器,模拟结果与实验结果吻合良好,验证了滤波器的设计思想.     

一种具有传输零点的Hairpin带通滤波器设计

本文通过在微带（hairpin）滤波器的谐振器上并联微带开路线，构成了一种新的hairpin带通滤波器。该滤波器在通带附近有一对传输零点，具有良好的频率响应以及频率选择特性。由于这种类型的微带滤波器实现传输零点不需要通过滤波器非相邻谐振器间的交叉耦合来获得，因此，设计过程非常简单。     

变容管电调微波带通滤波器

本文叙述采用梳状线结构的变容管电调微波带通滤波器的设计理论和方法。推导出梳状线带通滤波器的输入、输出耦合网络的参数条件,以补偿带通滤波器的谐振器之间电磁耦合随不同调谐频率的变化;并给出使带通滤波器的绝对带宽或通带回波损耗在调谐频率范围内变化最小时,梳状线谐振器的电长度应满足的相应条件,由此来保证电调带通滤波器在较宽的调谐频率范围内具有较高的通带回波损耗,且保持带通滤波器的响应形状和绝对带宽基本不变。此外,还讨论了由电调变容管的Q值引起的带通滤波器的通带有功损耗问题。文中给出了具体的设计公式。最后,给出了一个L波段变容管电调带通滤波器的研制实例和测试结果。     

Development of new miniaturised bandpass filter having ultrawidebandwidth

A new, compact, very-broadband bandpass filter, consisting of two-parallel-conductor short-circuited spurline resonators, quarter-wavelength long, is described. Approximate design formulas for the filter are derived. The chain matrix of the resonators is also obtained and used in predicting the filter response. It is found that this filter possesses a very wide bandwidth, more than 5:1. A microstrip filter having a passband from 1.8 to 9.2 GHz has been designed and tested with less than 1 dB insertion loss. There is also a reasonably good agreement between the experimental and theoretical performances. The developed filter is very attractive for wideband microwave integrated circuits due to its compactness and very wide bandwidth     

A Fully Integrated CMOS Active Bandpass Filter for Multiband RF Front-Ends

In this paper, design techniques for an integrated RF bandpass filter are discussed. A novel wide-tuning high-$Q$ active bandpass filter utilizing the active inductors is presented. Issues of the active inductor related to $Q$-enhancement, noise, linearity, and stability are considered. The circuit has been fabricated in an 0.18-$mu$m CMOS process, and the filter occupies the active area of 150$,times,$ 200 $mu$m $^{2}$. Measurement results show that the filter centered at 3.82 GHz with about 36-MHz bandwidth (3-dB) is tunable in frequency from about 1.92 to 3.82 GHz, and it exhibits $-$ 15- to 1-dB compression point at 2.44 GHz with approximately 60-MHz bandwidth while the dc power consumes 10.8 mW.      

Photonic bandpass filters with high skirt selectivity and stopband attenuation

A new photonic signal processor topology that simultaneously achieves both a high-Q and a high skirt selectivity and stopband attenuation filter response is presented. It is based on a novel dual-cavity bandpass optical structure in which two pairs of active fiber Bragg grating cavities are used with an optical gain offset to control the poles and stopband attenuation characteristics of the filter. This concept enables a large improvement in the filter stopband attenuation, rejection bandwidth, and skirt selectivity to be realized. Measured results demonstrate both a narrow bandpass bandwidth of 0.4% of center frequency and a skirt selectivity factor of 16.6 for 40 dB rejection, which corresponds to a 6.5-fold improvement in comparison to conventional single cavity high-Q structures. To our knowledge, this is the best skirt selectivity reported for a photonic bandpass filter to date. The new photonic filter structure has been experimentally verified and excellent agreement between measured and predicted responses is shown.     

新型折叠多模微带带通滤波器设计

文中提出了一种新型的小型化微带带通滤波器设计方案.方案所提微带带通滤波器的基本结构是折叠多模谐振器,该谐振器不仅具有谐振元件的特性,还能作为开路短截线.新型微带带通滤波器能够实现宽频带的通带响应,并在通带内具有较低的插入损耗和良好的阻带匹配特性,且在通带外额外产生了一对传输零点.本文给出了滤波器的等效电路分析和初步设计方案.该滤波器的最大优点在于进一步减小了滤波器尺寸,同时改善了滤波器的衰减极点,其中心频率为5.2 GHz.