基于开口环谐振器的双频通带可调滤波天线

该文提出了一款通带独立可调的高选择性双频滤波天线。首先设计了一款微带耦合式馈电的双频带通滤波器,通过在微带馈线上引入一个金属通孔,实现源负载耦合,改善裙边选择性。同时,给出了滤波器对应的等效电路模型。在此基础上设计了一款椭圆形单极子天线,利用滤波天线综合设计方法与滤波器集成实现滤波天线。单极子天线带宽覆盖滤波器带宽,仅改变开口环电长度即可实现中心频率可调。为了验证设计加工和测试了相应天线。结果表明,天线工作在2.31 GHz与3.27 GHz时,相对带宽分别为10.3%和7.7%,增益分别为3.2 dBi和4.1 dBi,有4个辐射零点,中心频率可调范围为1.8~4.8 GHz。测量与仿真结果基本吻合。     

A novel microstrip square-loop dual-mode bandpass filter with simultaneous size reduction and spurious response suppression

In this paper, a new capacitively stepped-impedance resonator(CSIR) is proposed to develop the microstrip square-loop dual-mode bandpass filter. Using this new design, simultaneous size reduction and spurious response suppression for the dual-mode bandpass filter can be achieved. An analytical formulation of this novel resonator is given in order to elucidate the spurious frequencies relocation design. Together with this formulation, a generalized dual-mode bandpass filter model is developed so as to ease the analysis of transmission zero and insertion loss. A prototype filter is designed at 900MHz with 1.5% fractional bandwidth. Significant spurious suppressions up to 33 and 35 dB are measured at 1.8 and at 2.7 GHz, respectively. A circuitry size reduction of 54% is achieved when compared with that of the conventional structure. Moreover, the CSIR allows frequency tuning and, thus, a varactor-tuned filter is designed and a measured tunable center frequency between 1.5-1.62GHz is demonstrated. Utilizing the proposed structure, not only size reduction,as well as spurious response suppression, but also center frequency tuning can be achieved.     

Electronically tunable ring resonator microstrip and suspended-substrate filters

Electronically tunable ring resonator microstrip and suspended substrate microwave filters with high tuning speed are presented. The filters are realised using two coupled ring resonators with GaAs varactors as the tuning elements. Computer optimised circuits are used at the input and the output to obtain better than 10 dB return loss across the tuning band. Tuning ranges of 1.075-2.25 GHz for the microstrip filter and 1.35-2.075 GHz for the narrower suspended substrate filter are predicted by computer simulation.<>     

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.     

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。     

基于双模谐振器的双通带可调谐滤波器设计

从理论上分析了开路支节加载双频谐振器的谐振模式,通过在谐振器末端加载变容二极管的方式,设计了一款双通带独立可调谐滤波器。通过调节谐振器末端变容二极管电容值大小来改变通带的中心频率,通过调节支节末端的变容二极管来调节通带的带宽。该滤波器的两个通带之间相互独立,调谐其中一个通带对另一个通带几乎没有影响。通过引入源与负载的耦合,使得双通带两侧各产生一个传输零点,提高了滤波器的选择性和带外抑制能力。最终设计出的滤波器第一通带的中心频率在1.08~1.19 GHz之间连续可调,绝对带宽在112~152 MHz之间连续可调;第二通带中心频率在2.07~2.22 GHz 之间连续可调,其绝对带宽在132~189 MHz 之间连续可调。在调谐过程中,通过调节中心开路支节末端变容二极管加载直流电压大小,实现调谐过程两通带带宽基本维持不变。     

Millimeter-wave tune-all bandpass filters

Distributed microelectromechanical varactors on a coplanar waveguide have been used to design a two- and four-pole bandpass tune-all filters. The two-pole initial bandwidth is 6.4% at 44.05 GHz with a mid-band insertion loss of 3.2 dB and with matching better than 15 dB. The four-pole initial bandwidth is 6.1% at 43.25 GHz with a mid-band insertion loss of 6.5 dB and with matching better than 10 dB. The use of microelectromechanical system bridges allows a continuous tuning for both center frequency and bandwidth. The varactors biasing network has been designed so that the center frequency and bandwidth can be tuned separately. The two-pole filter center frequency can be changed from 44.05 to 41.55 GHz (5.6% tuning range), while the bandwidth can be independently changed from 2.8 to 2.05 GHz. The four-pole filter center frequency can be changed from 43.25 to 40.95 GHz (5.3% tuning range) and the bandwidth can be changed from 2.65 to 1.9 GHz.     

BST-Varactor Tunable Dual-Mode Filter Using Variable ${Z}_{C}$ Transmission Line

Ferroelectric materials like barium-strontium-titanate (BST) have become attractive for microwave tunable circuit applications. This letter presents an investigation of BST-varactor tunable dual-mode filter using variable characteristic impedance or Z_C transmission line. The interdigital BST varactors are fabricated and modeled, which are then deployed to realize a bandpass filter with tunable bandwidth capability. The use of tunable impedance line provides additional flexibilities in the design of microwave tunable circuits. A tunable bandpass filter of this type with a center frequency of 1.8 GHz and a bandwidth tuning ratio of 1.15:1 is demonstrated experimentally.     

压电换能器电调七阶微带滤波器的设计

为了解决电容管电调滤波器插入损耗大的问题,该文设计了一款以压电换能器为电调元件、介质基片为微扰片的七阶平行耦合线电调滤波器。采用高频结构仿真器(HFSS)和先进的设计系统(ADS)对滤波器的结构参数进行联合仿真和优化,分析了滤波器的耦合系数和外部品质因数随微扰片间距变化的关系。将氧化铝陶瓷基板、压电换能器(PET)和微带滤波器组装在一起构成压电换能器电调滤波器,并用网络分析仪测量滤波器在不同直流电压下的S参数。测量结果表明,中心频率调谐范围为4.38~4.78 GHz时,通带的反射损耗大于10 dB, 插入损耗小于1.5 dB,达到了设计要求。     

基于近零介电常数超材料的液晶可调带通滤波器设计方法研究

可调带通滤波器是物联网、卫星通信、智能天线等系统中不可缺少的关键器件之一。针对目前对可调带通滤波器小型化、低成本和高集成度等特点的应用需求,提出了一种基于液晶材料的可调带通滤波器设计方法。通过微带传输线结构实现了近零介电常数(epsilon near zero,ENZ)超材料单元结构的设计,并利用ENZ超材料的窄通道隧穿效应有效实现了窄带滤波功能,通过将3个ENZ超材料单元结构串联从而完成了带通滤波器基本结构的设计。在此基础上,将微波液晶材料引入ENZ超材料的隧穿通道中,利用液晶材料在外部驱动电压作用下介电参数可变的特性,最终实现了对带通滤波特性的有效调控。全波数值仿真结果表明,所提出的基于ENZ超材料的液晶带通滤波器能够实现中心频率15.88~16.73 GHz的调控,从而验证了设计方法的有效性。     

数控电调带通滤波器的设计与制作

设计了一种新型电调谐带通滤波器,研究了数字信号控制滤波器电调谐的技术。采用数模转换器和高压运放实现数字信号与直流电压的转换;以变容二极管作为调谐元件;带通滤波器采用梳状微带线结构,并给出了结构参数。最后制作了一个由8位二进制编码控制的电调谐带通滤波器,其中心频率在300～1200MHz可调。测试结果与理论设计基本吻合。     

基于枝节加载开环谐振器的带阻滤波器设计

提出了一种具有良好谐波抑制功能的双枝节加载开环谐振器,加载枝节采用均匀阻抗结构,与同尺寸的开环谐振器相比,结构更紧凑,能够更好地抑制寄生模,而且可以达到更低的谐振频率。分析了加载枝节参数对带阻滤波器抑制二次谐波的影响。通过在加载的双枝节间引入集总可变电容,可以使谐振器具备谐波抑制性能的同时,实现中心频率可调的功能。基于双枝节加载环谐振器设计出一种可调带阻滤波器,中心频率可以在900MHz ~2. 65GHz 范围内调节,而且最低寄生阻带能够抑制到8GHz。     

一种毫米波调谐微带滤波器的研制

该文基于金丝键合工艺和薄膜工艺,实现了一种低插损、小型化毫米波调谐微带滤波器。首先提出了一种加载矩形孔的半波长开路可调谐振器,通过在不同矩形孔上键合金丝来改变谐振器的等效电感值,从而改变谐振频率。然后利用所提出的可调谐振器实现了一种Ka频段五阶调谐带通滤波器,通过改变键合金丝状态来调谐频率,实现仿真和实测结果之间的偏差修正,解决了在毫米波频段由于介电常数批次性差异以及加工误差等因素造成的窄带滤波器频率偏移的问题。为了验证其可行性,对五阶调谐微带滤波器进行仿真、优化、加工及测试。结果表明,该滤波器的通带可调范围为35.35~35.95 GHz,插入损耗小于4.6 dB,能够实现所需通带。     

Multilayer Dual-Mode Dual-Bandpass Filter

A dual-mode dual-bandpass filter for the U-NII bands is proposed and demonstrated. Its effective size reduction is achieved by using a multilayer configuration. The first and the third layers incorporate microstrip dual-mode bandpass filters with operating center-frequencies of f₁ =5.2 GHz and f₂ =5.8 GHz, respectively. The second layer is used as a common ground plane for both filters, which also serves as a decoupling interface. Capacitive coupling transition is used to connect both filters to I/O coplanar waveguide (CPW) ports. Single and dual-band passband filter prototypes are designed, fabricated, and measured in this work, thus validating the design principle. Designed topologies of single passband filters with center frequencies of 5.2 and 5.8 GHz exhibit an out-of-band rejection better than 40 dB with a 3 dB bandwidth of 5.8% and 6%, respectively. The proposed multilayer dual-passband response with center frequencies of 5.2 and 5.8 GHz provide band-to-band isolation better than 30 dB. Measured insertion losses are lower than 2.76 dB, with 3 dB bandwidth lower than 5%.     

作弊防控系统中独立可调双频带通滤波器设计

文章提出了一种独立可调双频带通滤波器.该滤波器主要由一对加载变容二极管的并联耦合短路线、一对加载变容二极管的λ/2开路谐振器和公共输入输出部分组成.变容二极管和并联耦合短路线并联构成一个谐振器,产生第一通带.λ/2开路谐振器加载变容二极管,产生第二通带.通过改变加载在变容二极管上的偏置电压来改变变容二极管的电容值,使谐振器的谐振频率发生偏移,从而调节滤波器工作频率.结果表明,第一通带和第二通带的中心频率变化范围分别为0.2~0.4GHz和1.2~1.42GHz,调节百分比分别为66.5%和15.4%.仿真与测试的结果吻合良好,证明该设计方法是有效的.该滤波器可应用到作弊防控系统中.     

双频带介质集成波导滤波器的设计

介绍了一种双频带带通滤波器,该滤波器源与负载之间的两条通路用来实现两个频带,且滤波器每条通路的阶数和带宽都可以灵活设计。为了实现小体积且方便与平面电路集成,滤波器用介质集成波导设计,采用折叠排列,用微带馈电。另外在公共端设计金属通孔使两条通路同时达到阻抗匹配,使两条通路互不影响。在X至Ku频段内设计了两个双频带带通滤波器,这两个滤波器的中心频率均为11和13 GHz。设计的带宽为200,380,400和200 MHz。实测结果与仿真曲线较为吻合。     

微型化Ka波段环形带线谐振腔LTCC带通滤波器

提出了一种微型化Ka频段带线带通滤波器设计方案.采用带有调谐枝节的环形谐振腔和带线耦合结构,利用低温共烧陶瓷(LTCC)技术设计并研制了一个相对带宽约10.4%的Ka频段带通滤波器,典型性能为在中心频率26.99 GHz处插入损耗小于1.3 dB,带内驻波比小于1.20:1,损耗起伏小于0.30 dB,滤波器的尺寸为4...     

双模方形带通滤波器的分析、建模及设计

本文报道一种利用谐振器中缺口位置设计双模带通滤波器的新方法.用这种方法既可以实现具有一对传输零点的双模带通滤波器,也可以实现无传输零点的双模带通滤波器.通过分析缺口位置对谐振器内电场模式分布的影响,建立了双模滤波器的拓扑结构图.利用全波仿真软件,基于不同的缺口位置设计了中心频率为2.05GHz,带宽为100MHz的两种...     

基于GaAs变容二极管的电调滤波器芯片设计

介绍基于GaAs变容二极管工艺的电调滤波器芯片的研究与设计,包括变容材料制备、二极管模型建立以及电路设计。设计数款电调滤波器,工作频段范围覆盖1~19 GHz。测试结果显示,电调滤波器具有超过一个倍频程的调谐范围,器件击穿电压大于+30 V。本文选取中心频率为2~5 GHz可调的一款电调滤波器进行详细介绍,控制电压范围为0~15 V,插入损耗在10 dB左右,输入和输出驻波(电压驻波比)均优于1.8。设计的系列化电调滤波器具有一致性高、小型化、低成本和免调试等优势,拥有良好的应用前景。     

Variable Bandpass Filters Using Varactor Diodes

A rectangular waveguide type variable bandpass filter for the 4-GHz bandpass has been proposed and tested. The bandpass width varies from 260 MHz to 1.02 GHz for a filter using varactor diodes. Two microstrip variable bandpass filters for the 6-GHz and 4-GHz bands are also proposed and tested. The passband width varies from 310 MHz to1.24 GHz for a varactor-diode coupled filter, and it varies from 380 MHz to 2.18 GHz for a filter which is composed of low-pass and high pass filters connected in cascade. The center frequency of the three filters can be changed arbitrarily.