Compact Planar Dual‐Wideband Bandstop Filters with Cross Coupling and Open‐Ended Stepped Impedance Resonators

This letter presents the design of a compact bandstop filter (BSF) operating at two frequencies. The proposed BSF consists of open‐ended stepped impedance resonators (OSIR) and an end‐shorted parallel‐coupled microstrip line (E‐PCML). The OSIRs are used to achieve the impedance‐controlled stopband positions. The wide BSF bandwidths are achieved through enhanced coupling of the E‐PCML. Explicit design guidelines are derived using a lossless transmission line model. To validate theoretical predictions, a prototype dual‐band BSF operating at 900 MHz and 2,100 MHz with fractional bandwidths of 72% and 36% respectively, is implemented in microstrip.     

Analysis of Novel Approach to Design of Ultra‐wide Stopband Microstrip Low‐Pass Filter Using Modified U‐Shaped Resonator

A novel microstrip low‐pass filter is presented to achieve an ultra‐wide stopband with 11 harmonic suppression and very sharp skirt characteristics. The filter is composed of a modified U‐shaped resonator (which creates two fully adjustable transmission zeroes), a T‐shaped resonator (which determines a cut‐off frequency), and four radial stubs (which provide a wider stopband). The operating mechanism of the filter is investigated based on a proposed equivalent‐circuit model, and the role of each section of the proposed filter in creating null points is theoretically discussed in detail. The presented filter with 3 dB cut‐off frequency has been fabricated and measured. Results show that a relative stopband bandwidth of 164% (referred to as a 22 dB suppression) is obtained while achieving a high figure‐of‐merit of 15,221.     

宽阻带三模谐振器微带带通滤波器设计

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。     

光子带隙结构在微带带通滤波器中的应用

介绍了两种带有一维光子带隙(Photonic Bandgap，简称PBG)结构的馓带带通滤波器。它们具有良好的慢波滞阻特性，同时在结构上又无须腐蚀接地板．而仅仅修改微带线的形状。计算仿真与测量结果基本相符合。     

Tri‐band Microstrip Bandpass Filter Using Dual‐Mode Stepped‐Impedance Resonator

This letter presents a compact dual‐mode tri‐band bandpass filter by using a short‐circuited stub‐loaded stepped‐impedance resonator (SIR) and a short‐circuited stub‐loaded uniform impedance resonator. Also, a hairpin SIR geometry is introduced to miniature the size of this filter while maintaining excellent performance. The use of a short‐circuited stub at the central point of the hairpin SIR can generate two resonant modes in two passbands. Its equivalent circuit structure is analyzed by using the even‐odd mode theory. For demonstration purposes, a tri‐band filter for the applications of the Global Positioning System at 1.57 GHz, Worldwide Interoperability for Microwave Access at 3.5 GHz, and wireless local area networks at 5.2 GHz is designed, fabricated, and measured.     

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.     

Microstrip Lowpass Filter with Very Sharp Transition Band and Wide Stopband

A novel lowpass filter with a very sharp transition band and wide stopband is proposed. The proposed filter is based on T‐shaped patches which are etched in symmetrical structures and folded open stub. To obtain a wide stopband, we have used stub loaded semi‐circle stepped‐impedance structures. By designing the resonator with high inductance and capacitance, a very sharp transition band is achieved. The proposed filter has a 3‐dB cutoff frequency at 2.37 GHz and a 40‐dB rejection at 2.44 GHz. The stopband with an attenuation level better than –13.2 dB is up from 2.4 GHz to 16 GHz, and consequently we have reached the high and wide rejection in stopband with compact size. Good agreements between the simulated and the measured results are presented.     

一种带输入输出抽头的新型阶梯式阻抗微带带通滤波器

本文提出了一种利用阶梯式阻抗微带线构造微型带通滤波器的新型结构。在该结构中引入以零相位方式接入的微带抽头，与带集总电容的阶梯式阻抗微带滤波器相配合，通过在通带两侧分别产生两个传输零点，很好地改善了滤波器的带通特性。     

Novel Quasi‐Elliptic Function Bandpass Filter Using Hexagonal Resonators with Capacitive Loading

A novel and compact elliptic‐function bandpass filter is proposed in this letter. The techniques of slot etching and the addition of open stubs are applied to enhance the self‐inductance and self‐capacitance of hexagonal open‐loop resonators. Thus, size reduction and improved transmission performance are obtained. Compared to the performance of the conventional design, the central frequency and insertion loss are reduced by 28% and 3.1 dB, respectively. Measurements show that the proposed filter has a fraction bandwidth of 23% at the central frequency of 1.84 GHz, and its insertion loss in the passband is less than ?1.5 dB. The bandpass filter occupies only 12 mm×21.2 mm (approximately 0.24λ_g×0.14λ_g).     

微声薄膜耦合谐振滤波器的仿真与设计

基于Mason模型,建立了微声薄膜耦合谐振滤波器的等效电路,实现了滤波器的快速仿真设计。将耦合谐振滤波器与梯形结构微声薄膜滤波器级联,改善了滤波器的矩形度、带外抑制等特性,并通过优化设计,提高了级联滤波器的相位线性度。     

Compact Dual‐Wideband Bandpass Filter with Multimode Resonator

A microstrip dual‐wideband bandpass filter using a multimode resonator (MMR) is proposed in this letter. The proposed MMR loaded with a T‐shaped open‐ended stub and a short‐ended stub exhibits triple mode characteristics, and a synthesis method is developed to illustrate the wide passband with independently controllable center frequencies and bandwidths. To verify this design methodology, a dual‐wideband filter with fractional bandwidths of 19.1% and 27.9% is designed and fabricated. The measured results agree with the simulations.     

微声薄膜耦合谐振滤波器有限元建模与仿真

针对一维等效电路仿真模型不能对滤波器振动模式进行仿真的局限性,建立了微声薄膜耦合谐振滤波器二维和三维的有限元模型,仿真分析了滤波器在对称谐振频率和反对称谐振频率下的振动模式,并通过频率响应分析得到了滤波器的S参数.仿真结果表明,采用有限元分析法可实现微声薄膜耦合谐振滤波器几何参数以及电极结构的优化设计.     

应用CMoL进行屏蔽微带圆盘谐振器的全波分析

本文应用圆柱坐标系中直线法原理,在圆柱坐标系中沿径向离散,利用变型的边界条件,推出适合于微带圆盘及圆环谐振器的计算公式和方法,并就微带圆盘谐振器进行数值说教计算,与用其它方法进行的计算结果和实验数据相比较,准确性令人满意。     

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。     

2.4GHz石英窄带低损耗声表面横波谐振滤波器

该文描述了一种工作频率在S波段的低损耗极窄带声表面横波谐振滤波器,解决了整机系统在高频率S波段载波近端的杂波抑制。采用一阶温度系数为0的石英基片及比瑞利型声表面波波速高1.6倍的声表面横波,制作出3dB带宽大于1‰的低损耗窄带谐振滤波器,其工作频率达2.4GHz,损耗为5.77dB,3dB带宽为3.0 MHz,在50Ω测试系统中测试,偏离中心频率±7 MHz的阻带抑制为25dB;在-40~+85℃内,频率漂移仅为705kHz。     

Open‐Ended Waveguide Antenna Using a Single Split‐Ring Resonator

This letter proposes an open‐ended waveguide antenna with a single split‐ring resonator. In contrast to the waveguide antennas incorporating multiple rings reported in a previous study, which exhibited narrow bandwidth, the proposed antenna uses only one ring to achieve broader bandwidth while keeping the aperture small. A single ring has a relatively low quality factor compared to multiple rings. The simulated and measured fractional bandwidth was 4.13% and 4.03%, respectively, which is much broader than the fractional bandwidth of about 1% demonstrated in a previous study. This simple technique can be used in many applications that require small apertures including near‐field probes and array elements.     

低频高阻带抑制SAW有源滤波组件

介绍了一种低频高阻带抑制SAW有源滤波组件的设计方法，并介绍了最新研制的滤波组件的性能。其中心频率18MHz，通带波动0.5dB，近端阻带抑制达105dB，远端阻带抑制大于95dB（其中三次谐波抑制大于75dB)，增益8dB。     

基于微带SIR的单环及双环双模滤波器设计

采用阶跃阻抗方环代替传统的均匀阻抗方环结构,设计一种基于阶跃阻抗谐振器的微带双模滤波器。为增强滤波器的带外抑制和谐渡抑制特性,将双模滤波器从单环结构扩展到双环,两环之间通过偏馈微带线耦合。通过一个中心频率为2．5GHz、带宽约300MHz的滤波器设计和仿真,证实了基于SIR的方环双模滤波器不但具有尺寸上的优势,而且能通过级联获得传输零点多、带外抑制高、谐波抑制好的优点。     

一种体声波滤波器仿真设计分析

文中着重阐述了基于微机电系统（Micro-Electro-Mechanical Systems，MEMS）技术制造的薄膜体声波谐振器／滤波器，简述了它的结构及原理，分析了其主要特征参数和设计方法，并设计了中心频率为2．4GHz，带宽为100MHz的带通滤波器，展示了薄膜体声波谐振器／滤波器的突出性能，为通信MEMS技术的微型化发展提供了更广阔的道路。     

Design of Balanced Dual‐Band Bandpass Filter with Self‐Feedback Structure

A balanced dual‐band bandpass filter based on λ/2 stepped‐impedance resonators and open‐loop resonators is proposed in this letter. By employing a type of self‐feedback structure, an extra transmission zero is introduced near the common‐mode resonance frequency, and the common‐mode signal is suppressed. The measured results indicate that the filter can operate in 2.46 GHz and 5.6 GHz bands, and the insertion loss is 1.85 dB and 1.9 dB, respectively. Also, better common‐mode suppression is achieved.