小型化SIR同轴腔体双通带滤波器研究

基于频率变换技术的双通带滤波器综合理论,应用阶跃阻抗谐振器(SIR)的基本原理,在双通带滤波器设计中引入λg/4型SIR同轴腔体谐振单元,设计了一种交叉耦合型拓扑结构的小型化同轴腔体双通带滤波器,相比于实际长度λg/4的传统滤波器,尺寸压缩了约50%。仿真结果显示,两个通带内回波损耗均大于20 dB,插入损耗小于0.1 dB,通带之间的阻带衰减特性良好。该滤波器的两个传输零点提高了阻带抑制度,满足了通信系统对滤波器小型化、低插损、高选择性的要求,能够广泛应用于双频带通信系统。     

基于阶梯阻抗谐振器的双频微带带通滤波器设计

设计了一种基于1/4波长阶梯阻抗谐振器(SIR)的交叉耦合微带双频带通滤波器,利用SIR终端加载的金属化短路通孔实现K倒置器,利用谐振器之间的级间耦合实现J倒置器,通过相邻谐振器之间的级联耦合和不相邻谐振器之间的交叉耦合,完成了四阶双频带通滤波器的设计。滤波器两个通带的中心频率分别为3.78GHz和8.69GHz,中心频率比大于2,对应的插入损耗分别为-1.28dB和-2.29dB,带内回波损耗分别为-12.38dB和-25.0dB。测量结果和仿真结果基本吻合,实现了双频带通滤波器的小型化和低损耗。     

改善开环谐振器间电耦合系数色散现象的微扰结构设计

以耦合矩阵综合方法设计的交叉耦合滤波器由于谐振器间耦合系数的色散现象,使滤波器的实际响应与理论综合得到的响应存在差异。针对此情况,首先研究了开环谐振器间电耦合系数随频率的变化趋势及其对交叉耦合滤波器中传输零点位置的影响,随后设计了一种加载于谐振器间的U型微扰结构,通过调节其物理尺寸及位置可以降低耦合系数的色散现象,优化滤波器带外传输零点的分布。基于上述思路,分别设计了传统CQ结构以及加载微扰结构的CQ结构滤波器,其中心频率和通带带宽分别为20.6 GHz和1.4 GHz,加载有微扰结构的滤波器其低频端带外零点相较于传统滤波器从18.6 GHz移动至19.4 GHz,且带内特性和高端传输零点均未受到影响,最终实测结果与仿真结果基本一致。     

一种宽阻带窄带腔体滤波器的设计

该文介绍了一种窄带带通腔体滤波器的原理和设计方法,通过加载电容原理,使滤波器的寄生通带远离通频带,并设计了带哑铃型横杆的谐振器结构,在谐振器连接点形成电压驻波零点,从而进一步抑制滤波器的寄生通带,实现了具有宽阻带的带通腔体滤波器。最后,利用微波仿真软件CST设计了一款中心频率为2.45 GHz,相对带宽为4.08%的窄带带通腔体滤波器。仿真结果表明,滤波器带外抑制高,阻带范围宽,通带内驻波良好,满足设计指标要求。     

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...     

双层基片集成波导双通带滤波器设计

根据频率变换法的双通带滤波器综合理论,采用矩形基片集成波导谐振腔作为基本谐振单元,通过谐振器之间直接耦合设计了一种双层结构的双通带基片集成波导滤波器,利用Ansoft HFSS建立滤波器模型并进行全波仿真。仿真结果表明,两个通带内回波损耗均大于20 dB,插入损耗小于0.5 dB,通带之间的阻带衰减特性良好,同时其尺寸压缩了约50%,较好地实现了滤波器的小型化,满足了工程需要的技术指标。     

双层基片集成波导双通带滤波器设计

根据频率变换法的双通带滤波器综合理论,采用矩形基片集成波导谐振腔作为基本谐振单元,通过谐振器之间直接耦合设计了一种双层结构的双通带基片集成波导滤波器,利用Ansoft HFSS建立滤波器模型并进行全波仿真。仿真结果表明,两个通带内回波损耗均大于20 dB,插入损耗小于0.5 dB,通带之间的阻带衰减特性良好,同时其尺寸压缩了约50%,较好地实现了滤波器的小型化,满足了工程需要的技术指标。     

一种新颖微带双通带带通滤波器的设计方法

本文提出了一种新颖的微带双通带带通滤波器的设计方法。该微带双通带滤波器由两个中心频率不同的滤波器组成,并采用耦合线实现外部耦合。设计中引入源与负载之间的耦合,得到了额外的有限频率传输零点,改善了滤波器的衰减特性。通过调节源与负载之间耦合的强弱,可以适当地调节传输零点的位置。经设计并加工了一款4阶微带开环结构双通带滤波器,实测响应与仿真响应吻合较好,验证了该方法的有效性。     

LTCC宽边耦合交指型超宽带滤波器设计

提出用交指型结构实现超宽带（UWB）带通滤波器的小型化,并给出了设计方法。该结构通过宽边耦合实现超宽带滤波器需要的较大耦合系数,并通过加宽带状线谐振器的宽度减少不必要的交叉耦合,简化了滤波器的设计。最终设计了一个中心频率为f0,相对带宽为58%的六阶交指带通滤波器,滤波器尺寸仅为8 mm×11 mm。从仿真结果看,该滤波器保持了传统交指型滤波器阻带特性好,寄生通带远的优点。     

双频带通滤波器的优化设计

利用阶跃阻抗谐振器优化,设计了一个工作在无线局域网(2.4/5.2GHz)的双频带通滤波器。通过奇、偶模分析,在阶跃阻抗谐振器理论计算公式基础上,根据不同的阻抗比条件,阶跃阻抗谐振器谐振频率比与阶跃阻抗高、低阻抗电长度之比的关系曲线,可以方便地确定阶跃阻抗谐振器的谐振频率和电长度,通过sonnet电路仿真软件验证了设计的合理性,并给出了用于无线通信2.4、5.2 GHz双频带通滤波器的设计结果。该带通滤波器可以分别在2.4、5.2 GHz处得到较好的通带性。由于交叉耦合的存在,该双频带通滤波器在两个通带端各有一个传输零点,以此来提高滤波器的通带频率选择性。最后,测量结果与仿真结果基本吻合。     

脊双模波导滤波器的分析及设计

介绍了一种能实现脊双模波导滤波器的新型结构,分析了其腔内模式的耦合极性,利用不同的耦合极性对频率响应的影响可实现具有一对传输零点的双模滤波器,也可实现无传输零点的双模滤波器.以相同脊谐振单元不同的放置方向组成的两种带通滤波器为例,利用AnsoftHFSS仿真得到了两种不同的频率响应,结果与理论分析一致.最后设计出了一个六阶三传输零点的双通带滤波器,带内插损均小于0.6 dB,回波损耗小于-15 dB.     

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.     

An original approach to the design of bandpass cavity filters withmultiple couplings

A novel approach to the design of general cavity filters with each cavity coupled to an arbitrary number of other cavities is presented. This approach is based on a suitable characterization of the filter structure which does not require one to model separately the cavities (resonators) and the coupling elements. Suitably defined equivalent admittances are associated with each cavity allowing one to design the filter structure once the parameters of a suitable low-pass prototype are given; an efficient procedure for the synthesis of such a prototype with equiripple passband response is also presented which allows one to arbitrarily prescribe transmission zeros placed in the complex plane (even asymmetrically). The described design approach is particularly convenient when the filter structure does not allow a simple modeling of the resonators and coupling elements separately. This is the case of slot-coupled cavity filters and of filter structures based on arrays of coupled transmission lines. It is also shown that the simplified design approach often adopted in the past, where only two coupled cavities at a time are considered, can produce large errors even in the case of filters with all attenuation poles at infinity (i.e., two couplings per cavity)     

Design of Dual-Band Bandpass Filters Using Stub-Loaded Open-Loop Resonators

In this paper, open-loop resonators loaded by shunt open stubs are proposed to design compact dual-band bandpass filters with improved out-of-band rejection characteristics. The second passband of the dual-band filter is obtained by tuning higher resonant modes of the open-loop resonator by the stub length and position. A tapped-line input/output feed structure is used for external coupling. Required external coupling is obtained by adjusting the tapping position and dimension of the stub-loaded resonator. A lossless transmission line model is used to determine the resonance properties of the resonator and the external quality factor. Theoretical predictions are verified by the experimental results of three dual-band filters.     

A novel coupling structure suitable for cross-coupled filters with folded quarter-wave resonators

A new class of coupling structure for cross-coupled filters with folded quarter-wave resonators is presented. The cross coupling mechanism is realized by magnetic coupling from the short ends of the resonator. The proposed magnetic coupling solves the problem of response limitation of folded quarter-wave resonator cross-coupled filters that were introduced previously using electrical cross coupling. Several quadruplet and trisection filters are proposed and fabricated. The measured results matched well with the theoretical prediction.     

微波线性相位双模介质滤波器

本文讨论了用双模介质加载谐振腔实现的微波线性相位滤波器结构，在非级联耦合的诸振腔之间引入一个交叉耦合，以改善通带内的时延平坦特性，给出了用模匹配法计算介质加载谐振腔的谐振频率和谐振腔之间耦合系数的方法。介绍了采用这种方法构成的滤波器的实际设计方法。最后制作了用这种方法设计出的滤波器，给出的实测结果表明它不仅可满足幅频特性的滤波要求，而且具有良好的通带时延特性。     

Novel Dual-Mode Dual-Band Filters Using Coplanar-Waveguide-Fed Ring Resonators

This paper presents a novel approach for designing dual-mode dual-band bandpass filters with independently controlled center frequencies and bandwidths. Two microstrip perturbed ring resonators are employed to obtain dual-mode dual-band responses. Novel feeding structures are introduced to simultaneously feed the ring resonators and conveniently control the coupling strength between resonators and feeding lines, resulting in a wide tunable range of external quality factors. Two kinds of filter configurations with compact size are proposed. Both of them provide sufficient degrees of freedom to satisfy various requirements of external qualify factors and coupling coefficients at both passbands. Therefore, the center frequencies and fractional bandwidths of both passbands can be independently tuned to desired specifications within a wide range. To verify the proposed method, four filters are implemented. The measured results exhibit dual-mode dual-band bandpass responses with high selectivity.     

一种双通带微带滤波器的设计

设计了由两个H-谐振器以边缘耦合方式组成的双通带滤波器。在两条平行微带线之间桥接一条微带线,构成一个双频谐振器。随着馈电位置与中间微带线间距的增大,双频谐振器的两个外部品质因数呈相反的趋势变化。随着两个谐振器间距的增大,双频谐振器间对应的两个耦合系数逐渐减小。由此特性,将两个谐振器组合可构成双通带滤波器。     

过模基片集成波导腔体滤波器设计

提出了一种过模基片集成波导(SIW)腔体滤波器。介绍了只由单个过模SIW 腔体构成的一阶滤波 器的原理。利用过模SIW 腔体中的基模实现模式交叉耦合,滤波器能产生一个位于通带任一边的传输零点(TZ)。 设计了一个由两个过模SIW 腔体级联成的二阶滤波器,该滤波器能产生两个传输零点。为了改善滤波器的阻带性 能,使用了非相似谐振器技术来实现寄生抑制。此外,阻带性能也可以通过增加基模谐振器的数量来改善。设计并 制造了含有两个过模SIW 腔体的二阶和三阶滤波器,仿真与测试结果吻合。     

Dual-Band Vertically Stacked Laminated Waveguide Filter Design in LTCC Technology

A new design method of dual-band filters with laminated waveguide (or substrate integrated waveguide) is proposed by taking advantage of the existence of multiple cavity modes. The major design concept is adequately choosing geometric shape of laminated waveguide resonators to control the frequency bands, and positions of open slots and feeding probes to realize the desired coupling coefficients and external quality factors at both bands simultaneously. Two design examples with third-order and quasi-elliptic filter responses are given and verified by experiments. By using the low-temperature co-fired ceramic technology, the laminated waveguide resonators are vertically stacked, and the filter size can be miniaturized.