非等长微带SIR平行耦合带通滤波器的设计

本文提出应用非等长微带SIR（阶梯阻抗谐振器）构成平行耦合带通滤波电路的设计方法。它保持等长SIR滤波电路能够有效抑制高次谐波的特点，又增加了设计的灵活性。本文同时给出应用级联矩阵计算这种滤波电路工作衰减的公式．可以方便地分析宽范围的频率响应。     

微带长度及阻抗比对SIR带通滤波器的谐波频率的影响

分析了微带长度及阻抗比对SIR带通滤波器的谐波参数的影响，并利用Angilent ADS仿真软件分别对不同长度及不同阻抗比的滤波器电路进行仿真分析，找出谐波频率随微带长度及阻抗比变化的规律。     

慢波结构SIR双频带通滤波器设计

本文通过分析阶梯阻抗谐振器（SIR）和慢波结构谐振器的特性,提出了利用SIR谐振器的寄生通带产生第二通带的双频带通滤波器设计方法,以达到滤波器小型化的目的;并基于0°馈电结构获取传输零点的原理对滤波器阻带性能进行优化。最后结合ADS仿真软件设计了一个中心频率在2.4GHz和5.2GHz的微带双频带通滤波器。仿真结果表明滤波器具有良好的带内带外特性。本文所设计的滤波器尺寸小,性能好,具有很好的实用价值。     

具有抑制谐波性能的微带带通滤波新电路

针对分布参数滤波网络存在寄生通带问题,本文提出一种新的微带带通滤波电路.对其滤波特性进行了理论分析,给出了电路的结构形式和有关计算公式.它由特定组合传输线与平行耦合微带线单元级联构成,结构简单.计算及实验结果表明这种新的滤波电路具有良好的谐波抑制特性.这种滤波电路用在微波振荡器或放大器输出端,可以有效地抑制谐波输出.     

趋化因子受体CXCR4与肺癌的研究进展

提出了一个利用三截面阶梯阻抗谐振器(SIR)的微带双通带滤波器,两个通带的中心工作频率分别为2.4 GHz和5.2 GHz.由二截面SIR的谐振特性可看出,采用三截面SIR不仅比二截面SIR设计自由度更大,有利于滤波器的设计和减小滤波器所占用的电路面积.该文分别从仿真和测试两方面对该滤波器进行了研究,设计结果显示所设计的双通带滤波器结构紧凑,且仿真和测试结果吻合很好.     

三截面阶梯阻抗微带双通带滤波器的研究

提出了一个利用三截面阶梯阻抗谐振器(SIR)的微带双通带滤波器,两个通带的中心工作频率分别为2.4 GHz和5.2 GHz.由二截面SIR的谐振特性可看出,采用三截面SIR不仅比二截面SIR设计自由度更大,有利于滤波器的设计和减小滤波器所占用的电路面积.该文分别从仿真和测试两方面对该滤波器进行了研究,设计结果显示所设计的双通带滤波器结构紧凑,且仿真和测试结果吻合很好.     

加载倒T形并联枝节的微带低通滤波器设计

针对传统的高低阻抗微带低通滤波器和开路端短截线微带低通滤波器体积较大、过渡带较缓且插入损耗较大的问题,采用高阻抗传输线单元加载并联倒T形枝节方法,构成带阻滤波支路,抑制了寄生通带,减小了滤波器面积。以7阶切比雪夫低通滤波器为例进行了设计和测试。实验结果表明,倒T形并联枝节滤波器截止频率为5.06 GHz,通带内最大插入损耗小于0.95 d B,在5.61~13.6 GHz内阻带抑制超过21 d B,而滤波器的面积比传统的开路端短截线微带低通滤波器减小20%。     

一种新型微带交指带通滤波器的设计

分析了四分之一波长阶跃阻抗谐振器(SIR)能够抑制寄生响应的特点和实现滤波器小型化设计的原理。利用SIR增加了设计滤波器的灵活度,实现了对L波段传统微带交指带通滤波器的改进,得到了基于SIR结构的新型微带交指带通滤波器。仿真试验结果证明:改进后的滤波器第一寄生响应向后推移1.4 GHz,整个滤波器的面积可以减少32%,该设计方法有效。     

X 波段阶梯阻抗滤波器设计

微带发夹型阶梯阻抗滤波器有尺寸小、成本低、易于集成和寄生通带可调节等特点,在微波电路中有着广泛的应用。文章设计了一个X 波段阶梯阻抗滤波器,中心频率为8.1GHz,带宽超过400MHz ,在7.9 GHz -8.3 GHz 的通带内插损优于3.5dB,带内波动小于1dB,在6.5GHz 和9GHz 处衰减大于50dB,滤波器尺寸为10mm*10mm。     

基于交指谐振结构的微带低通滤波器改进设计

提出一种微带低通滤波器改进设计方法.滤波器本身采用经典方法设计,通过在输入输出端口上添加交指型谐振器构成带阻滤波器,可将滤波器的适用带宽拓展50%以上.采用的交指型谐振器由8根容性交指和1根感性的高阻抗线并联而成,通过调整交指长度,可以方便地调节谐振器的谐振频率.设计并制作了两种改进结构,数值模拟和测量结果表明:通过引入交指结构,可以有效抑制微带低通滤波器的寄生通带,并且可以通过级联多个交指谐振器进一步扩展滤波器的适用频带.该设计方法还可用于带通等其他类型微带滤波器的寄生通带抑制.     

微波无线电通信系统的研究

随着通信技术的不断发展,无线电技术中的微波有源、无源部件的研究对于提高卫星通信系统以及雷达系统的性能具有非常重要的意义。本文主要围绕无线电收发信机中的微波有源、无源部件,结合微带传输线理论提出了抑制杂波的SIR电容藕合微带带通滤波器结构,详细分析了SIR谐振器结构通过调整谐振器的阻抗比实现杂波频率控制的机理,给出了SIR电容藕合带通滤波器的仿真结果。     

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。     

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.     

Bandpass Filters Using Parallel Coupled Stripline Stepped Impedance Resonators

Approximate design formulas for bandpass filters using parallel coupled stripling stepped impedance resonators (SIR) are derived. The formulas take into account the arbitrary coupling length as well as quarter-wavelength coupling. Some advantages of this filter are its abilities to control spurious response and insertion loss by changing the structure of the resonator. Using the design formulas two experimental filters were designed and fabricated and their performances closely matched design data.     

Design of microstrip bandpass filters with multiorder spurious-mode suppression

This paper proposes a bandpass filter design method for suppressing spurious responses in the stopband by choosing the constitutive resonators with the same fundamental frequency, but staggered higher order resonant frequencies. The design concept is demonstrated by a four-pole parallel-coupled Chebyshev bandpass filter and a compact four-pole cross-coupled elliptic-type bandpass filter. Each filter is composed of four different stepped-impedance resonators (SIRs) for which a general design guideline has been provided in order to have the same fundamental frequency and different spurious frequencies by proper adjusting the impedance and length ratios of the SIR. Being based on knowledge of the coupling coefficients and following the traditional design procedure, the resultant filter structures are simple and easy to synthesize. The measured results are in good agreement with the simulated predictions, showing that better than -30-dB rejection levels in the stopband up to 5.4f/sub 0/ and 8.2f/sub 0/ are achieved by the Chebyshev and quasi-elliptic filters, respectively.     

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.     

A Multilayered Parallel Coupled Microstrip Bandpass Filter With Embedded SIR Cells to Have a Broad Upper Rejection Band

This paper proposes a parallel coupled microstrip bandpass filter (BPF) with folded stepped impedance resonator (SIR) cells on the middle layer for spurious suppression. The folded SIR cells on the middle layer create a wide stopband by canceling the second and third harmonics of the parallel coupled microstrip BPF with suppression of over $-$50 and $-$30 dB, respectively. By selecting properly the impedance ratio (R) and physical length ratio $(alpha)$ of the folded SIRs, the parallel coupled BPF with a wide stopband can be implemented without causing a package problem of degrading the complete ground plane. The proposed BPF is designed and fabricated. Good agreement between the electromagnetic (EM) simulation and measurement is obtained.      

一种小型的交叉耦合阶梯阻抗谐振器带通滤波器

利用小型化的阶梯阻抗谐振器设计了一种交叉耦合带通滤波器.引入的交叉耦合结构在带外产生了一对传输零点以更好地抑制带外干扰信号而不影响通带特性.由于采用了小型化的阶梯阻抗谐振器,交叉耦合带通滤波器尺寸大为减小,同时寄生通带移向更高端.实验和仿真结果基本一致.