一种共面波导结构双模方形贴片带通滤波器

提出一种新型共面波导(CPW)结构双模方形贴片带通滤波器。该滤波器采用方形贴片作为谐振器,在方形贴片的两个对称的角上开两个相同的方形切角作为微扰使其简并模式分离并产生耦合,贴片与输入/输出CPW分别设计在介质基板的两个不同的面上。文中给出了该滤波器的结构以及通过仿真和实验获得的性能参数,结果表明该滤波器的通带带宽可在4.9%到7.4%的范围内调节,通带内的最小插入损耗为1.85dB。     

一种利用环形双模谐振器实现的带阻滤波器

提出了一种利用双模环形谐振器实现的带阻滤波器。该滤波器由一个对称的双模环形谐振器以及一段四分之一波长的平行耦合线组成。借助于在普通环形谐振器的两个相对边上添加一对小贴片,环形谐振器的两个简并谐振模式可以被可控的分离,从而可以构成带阻滤波器的工作频带。平行耦合线的作用是为了对双模谐振器进行馈电,同时也被用做两端口间的阻抗变换器。在理论分析之后,利用平面PCB工艺设计制作了滤波器样品,并对其进行了测量,进一步证明这种设计的有效性。     

一种新型双环双模带通滤波器

本文提出了一种由一个环形谐振器和一个微扰小环构成的新型双环双模带通滤波器。微扰小环具有两个可调参数,增加了调整双模的自由度,从而更容易地调节双模,便于实现滤波器的小型化。抽头输入输出耦合结构可以方便地调整双模滤波器的两个传输零点,从而改善滤波器的通带特性。最后实现了中心频率为2.41GHz,相对带宽为17.77%的双环双模带通滤波器,通带内插入损耗为0.67dB,回波损耗为17dB,且带外衰减大于20dB。     

一种共面波导结构双模圆环带通滤波器

提出了一种新型的用共面波导馈线结构实现的双模圆环带通滤波器。该滤波器采用传统的圆环作为谐振器,引入阶梯阻抗作为微扰使其简并模式分离并产生耦合。这样的微扰结构我们称之为环形阶跃阻抗谐振器,它与输入/输出共面波导分别设计在介质基片的两个不同的面上。文中给出了该滤波器的结构及通过仿真和实验获得的性能参数,结果表明该滤波器在带宽为11.4%时通带内的最小插损为1.42dB。     

新型的平面双模椭圆函数带通滤波器

根据传统的方形贴片双模滤波器,提出了一种新颖的带有两个切角的平面双模带通滤波器结构.该结构使用单个贴片谐振器并且没有耦合缝隙,通带两端各有一个衰减极点,有效减小了滤波器的辐射损耗.对该滤波器结构进行改进,又提出了一种带有两个相互正交、长度不等槽线的双模椭圆函数带通滤波器结构.该滤波器在中心频率1.8GHz处,回波损耗达到31.53 dB,通带内最小插损达到0.01 dB,3 dB相对带宽为19.44%.采用Ansotf公司的En-sem ble 8.0仿真软件进行的仿真研究.仿真结果表明该结构可以更加有效地减小辐射损耗,增加带宽,且体积比传统滤波器减小了约40%,有利于小型化.     

基于方形环谐振器的双模宽带滤波器设计

基于微带方形环谐振器,采用一种新的微扰方式来实现奇偶模分裂,并对其模式分裂机制进行分析。采用阶梯阻抗微带线结构实现输入/输出与双模谐振器之间的强耦合,构成了宽带带通滤波器。测试结果表明,该滤波器中心频率为4.9 7 G H z,通带内最小插损为1.3 3 d B,3 d B相对带宽为2 4.7 5%,并且具有准椭圆函数响应,改善了阻带抑制特性。     

基于半切双模介质谐振器的小型化差分滤波器

提出了一种基于半切双模介质谐振器的差分带通滤波器设计方法。半切双模介质谐振器由两个等同的半切矩形介质谐振器垂直交叉构成,并在顶端通过表面覆盖金属形成电壁,实现双模谐振器的小型化。该半切双模介质谐振器中存在着一组可被差分激励的简并模,通过微扰实现它们之间的耦合,同时它们能够被差分激励构建差分通带。最后,一种紧凑型差分双模介质谐振器滤波器被设计用来证实上述理论。仿真和实测结果表现出了高度吻合。     

基于微带贴片谐振器的高选择性双模双通带带通滤波器的研究

本文提出了基于微带贴片谐振器的高选择性双模双通带带通滤波器及一种模式分析算法.首次利用该算法分析了微带贴片的模式组成,计算了导模场的闭式解.微带贴片的耦合馈线同时作为谐振单元构成第二个通带,减小了结构尺寸.全波仿真分析（full wave analysis）结果及测试数据表明,与现有的双模双通带带通滤波器相比,本文设计的滤波器传输零点个数增加了2倍,达到11个,带外抑制度达到20dB,带内插损较小,仅为1.2dB,抑制了寄生通带.同时设计的拓扑结构复杂度较低,利于滤波器的小型化.     

脊双模波导滤波器的研究

介绍了一种利用脊谐振器产生的正交准TEM简并模实现脊双模波导滤波器的新方法。通过分析脊谐振器放置在主模传输波导中不同位置的特性,建立了耦合拓扑结构图,实现了三种不同类型的频率响应。利用全波仿真软件AnsoftHFSS,分别以方形和十字交叉这两种脊谐振器作为基本单元,设计出了两腔四阶的脊双模波导滤波器,两个滤波器的插损均小于0.2 dB,回波损耗小于–23 dB,仿真结果与预期吻合。     

一种多模微带方形贴片带通滤波器的设计

提出了一种多模方式工作的微带方形贴片带通滤波器。通常设计微带方形贴片滤波器主要是利用TM1,0,0和TM0,1,0这一对简并主模实现单模或双模的工作方式。但是这些滤波器尚存一些有待完善的地方,诸如带内插损偏大,带宽受限等等。本文设计的带通滤波器不使用主模,而是利用三个高次模分量,通过一种简单的微扰方式和馈电方式激励起除简并主模以外的三个高次模分量,并使之相互耦合实现通带。仿真和测量结果充分说明,这种滤波器能够实现宽频段的通带响应,并且在通带内具有很低的插损和良好的阻抗匹配特性,能够广泛地适用于微波平面电路。     

A reduced-size dual-mode bandpass filter with capacitively loaded open-loop arms

A novel type of dual-mode microstrip bandpass filter using degenerate modes of a dual-mode microstrip square loop resonator with capacitively loaded open-loop arms is proposed. Such a dual-mode bandpass filter with a 0.75% bandwidth at the center frequency of 1.603 GHz is designed and fabricated to demonstrate the design of reduced-size microstrip filters. It is shown that the proposed filter has a size reduction of about 59% at the same center frequency, as compared with the dual-mode bandpass filters such as microstrip patch, cross-slotted patch, square loop and ring resonator filter.     

A novel dual-mode bandpass filter with wide stopband using the properties of microstrip open-loop resonator

A novel dual-mode microstrip square loop resonator is proposed using the slow-wave and dispersion features of the microstrip slow-wave open-loop resonator. It is shown that the designed and fabricated dual-mode microstrip filter has a wide stopband including the first spurious resonance frequency. Also, it has a size reduction of about 50% at the same center frequency, as compared with the dual-mode bandpass filters such as microstrip patch, cross-slotted patch, square loop, and ring resonator filter.     

Dual-mode microstrip bandpass filter using ring of arrows resonator

A dual-mode microstrip bandpass filter using the degenerate modes of a modified square ring structure is proposed. The size of the new structure is 50% less than conventional dual-mode bandpass microstrip square resonator filters at the same centre frequency. Measurements are in good agreement with designed values.     

Compact dual-mode elliptic-function bandpass filter using a singlering resonator with one coupling gap

A novel microwave dual-mode elliptic-function bandpass filter with one coupling gap structure is proposed. This filter has a 4.7% bandwidth at 1.805 GHz with 1.73 dB insertion loss. The filter provides less field perturbation of the ring resonator than conventional filters. Without the output coupling gap between the feed line and the ring resonator, a low insertion loss has been obtained. This compact, high performance filter is useful for mobile and personal communication systems     

A novel self-coupled dual-mode ring resonator and its applications to bandpass filters

A novel dual-mode ring resonator with self-coupled segments, called a self-coupled ring resonator, is proposed. The self-coupling between ring segments provides the same mode perturbation effect as the conventional methods of adding stub, cutting notch, or varying line impedance on the ring resonator. The mode perturbation and transmission-zero generation due to the self-coupling effect are analyzed with the even-odd mode theory. The self-coupled ring resonator can have the capacitive or inductive perturbation simply by controlling the impedance ratio and coupling coefficients of self-coupled sections. For both perturbation cases, the transmission zeros exist at even multiples of the passband center frequency, resulting in wide stopband range. Also, only for the capacitive perturbation case, two transmission zeros are found on both sides of the passband, which brings a pseudo-elliptic bandpass response. In comparison with the regular uniform ring resonator, the self-coupled ring resonator takes shorter ring length, giving the compact size feature when applied to a bandpass filter design. A 2.45-GHz low-temperature co-fired ceramic bandpass filter based on the self-coupled ring resonator was designed to verify the proposed theory.     

Miniaturized dual-mode bandpass filter using inductively loaded cross-slotted patch resonator

An inductively loaded cross-slotted patch resonator is presented to build up a miniaturized dual-mode bandpass filter. By terminating the cross-slot on the square patch with the T-shape slot stubs, the resonant frequency is exhibited to be largely lowered due to an additional inductive loading, implying a capacity in size-miniaturization. In parallel, the rectangular slit is introduced at the four sides of the cross-slotted patch to facilitate the tightened parallel coupling between the feeders and resonator. A dual-mode filter with the patch size of /spl lambda//4 squared is then designed and predicted results are evidently supported by measurement.     

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.     

十字形贴片双模微带带通滤波器

基于传统的贴片型双模微带带通滤波器,提出了一种结构新颖、简单的滤波器.该结构是在十字形贴片谐振器上刻蚀正交的T形槽通过中心处的方开槽相连.对该结构进行优化,优化后的滤波器能在通带两侧都产生衰减极点,提高阻带的抑制能力,同时保证滤波器的小型化.该滤波器仿真结果表明通带中心频率为2.75 GHz,最大回波损耗优于-32dB,通带内最小插入损耗为0.60dB,3dB带宽达到59.8％,实测和仿真结果相一致.