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交指带通滤波器是工程应用中常用的带通滤波器,但随着产品的小型化及带外抑制性能要求的多样化,常规交指带通滤波器在使用上受到较多限制。文中设计了一种新型SIR交指型微带带通滤波器结构,对常规交指微带带通滤波器进行小型化以及抑制性能优化。这种滤波器通过引入1 4波长SIR结构缩小单个谐振单元尺寸进行小型化,并引入发夹结构,通过其自身谐振特性以及交叉耦合在左端引入一传输零点,达到改善抑制性能的目的。通过HFSS建模仿真比对了同指标的两种结构滤波器特性,分析得出各自适用的抑制要求。测试结果表明,设计的带通滤波器性能曲线与仿真曲线相吻合,符合设计要求。 相似文献
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介绍了一种新颖的微带三模谐振器,由该谐振器构成的微带滤波器具有较宽的通带以及较好的带外抑制。对传统的单模微带环形谐振器结构进行优化,使谐振器在通带内具有三个谐振点,并且在通带边缘有四个对称衰减极点。引入的阶梯阻抗谐振单元使得微带三模谐振器具有良好的带外抑制。依据传输线原理对宽阻带三模谐振器进行了分析,并完成了中心频率为1090 MHz的宽阻带带通滤波器设计和加工,其实际测试结果与软件仿真结果具有良好的一致性。 相似文献
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设计了一种基于并联耦合线谐振节的窄带带通滤波器。该滤波器由常见平行耦合线带通滤波器与并联耦合线谐振节构成。利用并联耦合线谐振节结构的特性,借助ADS软件设计了一个中心频率为4.9 GHz的窄带带通滤波器。仿真结果表明,其3 dB带宽为236 MHz,矩形系数为2.8。该滤波器具有良好的带外抑制能力和更加陡峭的通带到阻带过渡。 相似文献
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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. 相似文献
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设计了一种由对称L型缺陷微带结构实现的新型频率可调带通滤波器,并给出了相应的等效电路;对具有该结构的单频带带通滤波器的S参数频响特性进行了仿真与分析,并计算了耦合系数;依据上述结构设计制作了一种可调谐的双频带带通滤波器,并对其谐振频率的可调性进行了分析。结果表明:所制滤波器的谐振频率分别为2.4 GHz和3.5 GHz,相对带宽分别为4.63%和4.95%,有效电路尺寸仅为26.0 mm×1.2 mm。该L型缺陷微带结构带通滤波器具有结构简单紧凑、尺寸小、频率选择性好和谐振频率独立可调等优点。 相似文献
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Wide-stopband microstrip bandpass filters using dissimilar quarter-wavelength stepped-impedance resonators 总被引:1,自引:0,他引:1
Shih-Cheng Lin Pu-Hua Deng Yo-Shen Lin Chi-Hsueh Wang Chun Hsiung Chen 《Microwave Theory and Techniques》2006,54(3):1011-1018
Wide-stopband and compact microstrip bandpass filters (BPFs) are proposed using various dissimilar quarter-wavelength (/spl lambda//4) stepped-impedance resonators (SIRs) for multiple spurious suppression. The use of /spl lambda//4 SIRs is essential in widening the filter stopband and reducing the circuit size. By properly arranging the individual /spl lambda//4 SIR, which has the same fundamental resonance frequency f/sub 0/, but has different spurious (harmonic) resonance frequencies, and also carefully misaligning the maximum current density nodes, several higher order spurious resonances may be suppressed so that a BPF with wide stopband may be realized. In this study, the basic concept of multiple spurious suppression is demonstrated by thoroughly investigating the spurious characteristics of the fourth-order interdigital BPFs, which consist of two different types of /spl lambda//4 SIRs. To widen the rejection bandwidth, the fourth-order coupled-resonator BPFs based on three and four different types of /spl lambda//4 SIRs are implemented and carefully examined. Specifically, a very wide-stopband microstrip BPF composed of four dissimilar /spl lambda//4 SIRs is realized and its stopband is extended even up to 11.4f/sub 0/ with a rejection level better than 27.5 dB. 相似文献
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Tsung-Nan Kuo Wei-Chiang Li Chi-Hsueh Wang Chun Hsiung Chen 《Microwave and Wireless Components Letters, IEEE》2008,18(6):389-391
Novel compact microstrip bandpass filters (BPFs) with extended stopband are proposed using both quarter-wavelength (lambda/4) stepped-impedance resonators and bandstop embedded resonators. First, by properly designing the impedance and length ratios of the stepped-impedance resonators, the developed filter may be made compact and its spurious harmonics may be pushed to the higher frequency region. Next, by suitably designing the bandstop structure so as to suppress the lower spurious harmonics of stepped-impedance resonators and then embedding the bandstop structure into the lambda/4 resonators, one may realize the BPFs with wideband spurious suppression. In particular, by connecting the bandstop embedded resonators to the input/output ports, a compact fourth-order BPF of dimension 0.089 lambdag times 0.27 lambdag is implemented and its stopband is extended up to 8.25 f 0 with an adequate rejection of greater than 32.49 dB, where f 0 is the passband center frequency and lambdag is the microstrip guided wavelength at f 0. 相似文献
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In this letter, spurious passband suppression in parallel-coupled stacked stepped-impedance-resonators (SIRs) bandpass filters (BPFs) by means of open-stub lines is proposed and implemented. These filters are composed of parallel-coupled stacked SIRs and open stubs. Moreover, the structure with tapped feeding is employed to create transmission zeros near both sides of the passband skirt. The proposed structure can improve the harmonic suppression so that a wide upper stopband with a satisfactory attenuation level would appear in this BPF. Measured results of the fabricated circuits show that the idea works very well 相似文献
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This article presents a compact microstrip dual-band bandstop filter (BSF), in which one λg/4 defected ground structure (DGS) pair is utilised to realise one stopband while two stepped impedance resonators (SIRs) help obtain another stopband and suppress the spurious harmonics. The design strategies and the equivalent circuits are introduced in detail. The measured results indicate 43.8% and 18.7% fractional bandwidth in the two stopbands (2.4 GHZ and 5.2 GHz) respectively, and the return loss is greater than 15 dB in the whole passband. In addition, size reduction can be conveniently achieved by adjusting the length of the SIRs and DGS. 相似文献
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《Microwave and Wireless Components Letters, IEEE》2008,18(5):320-322
This letter presents a miniaturized dual-band narrow bandpass filter (BPF) using meandering stepped impedance resonators (SIRs) with a new coupling scheme, which exhibited a size reduction of 50% compared with the traditional direct coupling structure at the same frequency, while the new structure can generate three transmission zeros in the insertion loss response. To validate the design and analysis, two dual-band BPFs centered at 2.4-GHz/5.2-GHz and 2.4-GHz/5.7-GHz for WLAN application were fabricated and measured. It is shown that the measured and simulated performances are in good agreement. The BPFs achieved insertion loss of less than 2 dB and return loss of greater than 16-dB in each band. 相似文献
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High-selectivity single-ended and balanced bandpass filters (BPFs) using dual-mode ring resonators and coupled lines loaded with multiple stubs are proposed in this paper. With the help of the loaded short-circuited and open-circuited stubs, six deep transmission zeros (TZs) from 0 to 2f0 (f0: center frequency of the passband) can be realized in both of single-ended and balanced BPFs to improve the stopband suppressions. The functions of the loaded short/open stubs and calculated analysis of TZs’ positions have been presented. For further demonstration, two examples of single-ended BPF and balanced BPF with high common-mode suppression are designed and fabricated, whose center frequencies are both at 2.1 GHz. Their measured 3-dB fractional bandwidths are 23.7% and 24.7% (differential-mode), respectively. The simulated results and measurements of these two filters are in good agreement. 相似文献
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《Microelectronics Journal》2015,46(1):121-124
This study presents a quadruplexer (1.8/2.4/3.5/5.8 GHz) with compact size, high isolation, low insertion loss and wide stopband based on the multi-mode resonators. The quadruplexer is composed of four pairs of coupled multi-mode resonators (uniform impedance resonator, UIR and stepped impedance resonators, SIRs) and the source–load coupling lines. Each channel (passband) can be easily determined by tuning the impedance ratio (K) and length ratio (α) of the SIRs so as to implement a 2-order bandpass filter individually. The source–load coupling lines are designed to correspond to the quarter-wavelength of the center frequency at each channel. The proposed quadruplexer shows a simple configuration, an effective design method and a small circuit size. 相似文献
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A surface-acoustic-wave (s.a.w.) band-elimination filter has been developed employing s.a.w. resonators composed of interdigital transducers with a large number of electrodes, exhibiting more than 80 dB stopband rejection with a passband attenuation of less than 1 dB. 相似文献
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《Microwave and Wireless Components Letters, IEEE》2008,18(9):581-583
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This letter describes a method for synthesizing a general in-line prototype filter presenting one or two transmission zeros without using cross couplings; the basic topology is constituted by resonators coupled through inverters, with input and/or output taken at the second and/or last but one resonators. In this case, the first and last resonators, tuned at frequencies in the stopband, produce two zeros in the transfer function. It is shown that, even if it is not possible to exactly synthesize this structure with extracted poles techniques, an approximated design procedure can be derived; the procedure is based on the synthesis of a low pass prototype with multiple couplings starting from source and/or load, followed by suitable network transformations. This design technique can be easily implemented in case of classical combline or interdigital filters. 相似文献