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。     

应用于WLAN&WiMAX的小型化SIR可调双通带滤波器

对传统双频段耦合方案进行改进,提出一种新型双通带滤波器结构。该滤波器由两个对称阶跃阻抗谐振器(SIRs)组成,通过调节SIR的电长度,可以得到中心频率可调的通带。为了验证设计与分析的正确性,提出和设计了3个双通带滤波器。Ⅰ型滤波器两个通带的中心频率分别为2.4 GHz和3.5 GHz,相对带宽分别为5.8%和13.7%;Ⅱ型滤波器两个通带的中心频率分别为3.5 GHz和5.2 GHz,相对带宽分别为5.7%和9.2%;Ⅲ型滤波器两个通带的中心频率分别为2.4 GHz和5.2 GHz,相对带宽分别为6.3%和5.4%。Ⅰ型和Ⅱ型滤波器均适用于宽带互通微波互联接入(Wi MAX)和无线局域网(WLAN)应用。Ⅲ型滤波器适用于双频WLAN应用。对所有滤波器进行加工与实测,测试结果与仿真结果吻合较好。     

具有可控双陷波特性的超宽带滤波器设计

在多模谐振器的基础上,设计了一种新型的具有双陷波特性的超宽带滤波器。该滤波器在十字形谐振器的基础上加载了一对阶跃阻抗谐振器及两组短路反耦合线结构。设计得到的滤波器尺寸紧凑,且可实现滤波器谐振频率及陷波点的独立可控。测试可得滤波器的通频带为1.8~12.1 GHz,3 dB相对带宽为148%,通带内插入损耗小于1 dB,两个陷波点频率分别位于5.15 GHz和6.98 GHz。结果表明,该超宽带滤波器能有效地抑制WLAN频段和C波段卫星信号的干扰,与仿真结果吻合良好。     

基于双同轴阶跃阻抗谐振器的带通腔体滤波器的设计

介绍了一种减小腔体滤波器体积的设计方法。分析了双同轴阶跃阻抗谐振器的谐振条件和未加载Q值,依据滤波器理论和运用HFSS软件设计了一个基于双同轴阶跃阻抗谐振器的带通腔体滤波器。在3.7～3.9 GHz的频带内,该滤波器插入损耗小于0.5 dB,回波损耗大于20 dB,测试与仿真结果相吻合。该滤波器具有体积小、结构简单易于加工等优点。     

宽阻带小型化双频带通滤波器

文中提出了一种具有宽阻带的紧凑型双频带通滤波器,它采用了折叠短路枝节负载谐振器、紧凑型微 带单元谐振器(CMRC)和阶跃阻抗谐振器结构。由于多个谐振器产生了五个可控传输零点(TZ),该滤波器实现了两个 通带之间的良好隔离度以及宽阻带特性。制作并测试了尺寸紧凑的双频带通滤波器实验样品,测试结果显示,第一通 带和第二通带的中心频率/ 插入损耗分别为0. 66 GHz/0. 8 dB 和1. 73 GHz/0. 7 dB,阻带频率高达10. 5 GHz,抑制水平 超过15 dB。     

基于加载非对称开路枝节谐振器的带通滤波器

基于新型的加载非对称开路枝节的阶梯阻抗谐振器,设计了一种具有高频率选择性的单频微带滤波器.该滤波器采用非对称的开路枝节作为容性负载,抑制高次杂散频率,具有较宽的上阻带,中心频率(2.4 GHz)处的插入损耗为0.6 dB.与传统结构相比,该滤波器在相同的谐振频率下尺寸减小了45％.调整新型阶梯阻抗谐振器的尺寸,还能实现中心频率为3.5 GHz单频和2.4 GHz/3.5 GHz双频带通滤波器.     

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.     

基于新型阶跃阻抗谐振器的微带双带带通滤波器

提出了一种小型多层低温共烧陶瓷(LTCC)双带带通滤波器的结构并给出其设计方法。该多层微带带通滤波器由两个中心频率不同的滤波器组成,均用新型阶跃阻抗谐振器(SIR)作为谐振单元,有效地缩短谐振器的长度。采用多层LTCC技术实现尺寸的小型化,并且获得较高的阻带抑制。经测试表明该滤波器能够在5.2GHz和6.5GHz工作,插入损耗均小于2dB,谐波抑制能力强,在小型化微波通信系统中有着广泛的应用前景。     

具有双陷波特性的超宽带带通滤波器

采用修改的多模谐振器(MMR)结构,通过输入输出端开槽形成交叉耦合,实现了一种结构紧凑的超宽带(UWB)带通滤波器。修改的多模谐振器在通带中能产生两个奇模、三个偶模,加载的阶跃阻抗开路枝节在通带的两边产生两个传输零点,提高了边缘选择性。同时在滤波器下方耦合双模阶跃阻抗谐振器形成具有双陷波特性超宽带带通滤波器,利用HFSS13.0验证。结果表明:该滤波器通带在2.61~11.21 GHz,其陷波频率分别发生在5.61,7.81 GHz,能有效抑制WLAN和X频段卫星通信系统对超宽带通信系统的影响,可适用于超宽带无线通信系统。     

Compact and Low Loss Dual-Band Bandpass Filter Using Pseudo-Interdigital Stepped Impedance Resonators for WLANs

In this letter, pseudo-interdigital stepped impedance resonators (PI-SIRs) are used to design the bandpass filter (BPF) with dual-band response. By tuning the impedance ratio (K) and physical length of SIRs, the BPF has good dual-passband performances at 2.4/5.2GHz and high isolation between the two passbands. It is shown that the dual-band BPF has a smaller area and lower insertion loss in comparison of previous works. Good agreement is shown between the full-wave electromagnetic simulation and the measurement     

Compact multilayer dual-band bandpass filter design using stepped impedance resonators

Compact dual-band bandpass filter (BPF) for the 5th generation mobile communication technology (5G) radio frequency (RF) front-end applications was presented based on multilayer stepped impedance resonators (SIRs). The multilayer dual-band SIR BPF can achieve high selectivity and four transmission zeros (TZs) near the passband edges by the quarter-wavelength tri-section SIRs. The multilayer dual-band SIR BPF is fabricated on a 3-layer FR-4 substrate with a compact dimension of 5.5 mm ×5.0 mm ×1.2 mm. The measured two passbands of themultilayer dual-band SIR BPF are 3.3 GHz -3.5 GHz and 4.8 GHz -5.0 GHz with insertion loss (IL) less than 2 dB respectively. Both measured and simulated results suggest that it is a possible candidate for the application of 5G RF front-end at sub-6 GHz frequency band.     

A Compact Dual-Band Bandpass Filter Using Meandering Stepped Impedance Resonators

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.     

Microstrip dual-band bandstop filter of defected ground structure and stepped impedance resonators

This article presents a compact microstrip dual-band bandstop filter (BSF), in which one λ_g/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.     

Compact triple-passband bandpass filter based on new modified stepped impedance resonators

This study proposed a triple-passband bandpass filter with compact size, low loss and high passband selectivity. The filter includes two coupled stepped impedance resonators (SIRs) and two embedded stub-loaded stepped impedance resonators (SL-SIRs), connected with coupling scheme at the symmetric plane of the filter. The filter is designed to have triple-passband at 2.4, 3.5 and 5.2 GHz for worldwide interoperability for microwave access (WiMAX) applications. By properly tuning the impedance ratio and physical length ratio of the SL-SIRs, the three passbands can be easily determined, at the same time, achieving the high passband selectivity and wide stopband. Besides, the transmission zeros near passband edges of each passband are generated by the proposed filter with cross-coupling structure. The measured results are in good agreement with the full-wave electromagnetic (EM) simulation results.     

A simple and effective method for microstrip dual-band filters design

A new type of novel low loss dual-band microstrip filters using folded open-loop ring resonators (OLRRs) is presented in this letter. Both magnetic and electric coupling structures are implemented to provide high performance passband response. The first passband and second passband of the designed dual-band filter can be easily and accurately shifted to a desired frequency band by adjusting the physical dimensions of OLRRs. Finally, the 2.4-GHz/5.7-GHz and 2.4-GHz/5.2-GHz dual-band filters are illustrated and measured in this letter.     

基于SRR-DGS 新型高选择性带通滤波器的设计

通过在阶梯阻抗谐振器(Stepped Impedance Resonators, SIR)上加载开口谐振环缺陷地结构(Split- Ring Resonator Defected Ground Structure, SRR-DGS),设计了一款具有高选择性和较好带外抑制性能的带通滤波器。 测试结果表明,该滤波器的3 dB 工作频带为2. 56 ~2. 77 GHz (7. 9%),带内最大插入损耗为0. 8 dB。此外,在通带 两侧各有两个传输零点,分别位于2. 17 GHz、2. 48 GHz、2. 86 GHz 和3. 81 GHz,带外抑制均大于30 dB,表明该滤波 器具有较好的带外抑制特性。同时,仿真与测试结果吻合较好,验证了该滤波器设计方法的有效性。     

Synthesis of dual-band bandpass filters using successive frequency transformations and circuit conversions

A novel method is proposed to synthesize dual-band bandpass filters (BPFs) from a prototype low-pass filter. By implementing successive frequency transformations and circuit conversions, a new filter topology is obtained which consists of only admittance inverters and series resonators, and is thereby easy to be realized by using conventional distributed elements. A dual-band BPF with center frequencies of 1.8GHz and 2.4GHz is designed and fabricated using microstrip lines and stubs. The simulated and measured results show a good agreement and validate the proposed theory.     

Microstrip bandpass filters using coupled feed lines for third and fourth generation communications

In this paper, two compact tuneable bandpass filters (BPFs) based on the coupled feed lines are introduced. To approach a compact size, the coupled feed lines are bended. To design a high performance single-band bandpass filter (BPF), coupled feed lines are loaded by T-shaped stubs (as main resonators) and rectangular stubs (as suppressor stubs). Also, the mechanism of coupled feed lines combining with T-shaped open stubs is analyzed to show a tunable passband. The dual-band BPF includes two big radial-stubs, two small radial-stubs, two T-shaped structures and spiral coupled feed lines. The LC model of big radial-stubs is analyzed to compute the equation of transmission zero using its transfer function. The passband frequency of single-band BPF resonates at 2.12 GHz (3G) with corresponded insertion loss of 0.83 dB. Also, for dual-band BPF, the measured insertion-losses of first and second passbands are close to 0.8 and 1.1 dB, respectively. The frequency responses of BPFs are easily adjusted by altering the physical dimensions, demonstrating a adjustable performance. To verify the correct operation of circuits, the proffered filters are implemented and tested.     

Compact ultra-wideband bandpass filter using broadside coupled hairpin structures on multilayer liquid crystal polymer substrate

A novel ultra-wideband (UWB) bandpass filter (BPF) using a broadside- coupled hairpin structure and multilayer organic liquid crystal polymer (LCP) technology is presented. To suppress stopband harmonic response, folded stepped impedance structures were adopted as hairpin resonators in the design. The proposed filter has been investigated numerically and experimentally. Multilayer LCP technology was used to implement designed UWB BPF. Good agreement between simulated and measured results of the proposed filter was observed. They show that the fabricated UWB BPF has a good performance, including a small insertion loss, a flat group delay with a variation within 0.1 ns in most of its passband, a wide stopband from 11.0 20.0 GHz with a high rejection level up to 20.0 dB, and a very compact size of 9.8 x 7.5 mm (0.36 lg x 0.27lg, where lg is the guided wavelength of 50 V microstrip line at 6.85 GHz).