SIR实现的新型毫米波UWB滤波器

提出了一个用阶跃阻抗谐振器(SIR)实现的毫米波超宽带(UWB)滤波器。滤波器的基本单元是一个由半波长微带线谐振器和SIR组成的三模谐振器。该谐振器采用SIR结构,从而达到阻带宽、结构紧凑,且能很好地改善带外抑制。为了进一步改善阻带特性,该三模谐振器与半波长谐振器平行耦合形成新型的滤波器。该滤波器有多个传输极点和传输零点,形成陡峭的通带边缘特性和很宽的阻带。实验测得滤波器的-3 dB相对带宽为35.7%,通带内的插入损耗约为-1.7 dB。插入损耗低于-17 dB的高频端阻带可到76 GHz。滤波器的仿真结果和测试结果基本吻合。     

高带外抑制特性微波陶瓷波导滤波器的设计

介绍了陶瓷波导滤波器的设计理论,采用耦合通槽分别与浅、深耦合盲孔的组合结构来满足正、负耦合带宽要求,通过调整3~6腔体的交叉耦合来改善滤波器传输曲线的对称性,同时实现滤波器近端和远端的带外抑制,在此基础上设计了一款5G基站用六腔陶瓷波导滤波器。在该滤波器的优化过程中,详细讨论了3~6腔体交叉耦合通槽的相对位置偏移量和交叉耦合通槽的长度对滤波器传输零点位置、近端和远端带外抑制特性的影响,并给出了相关的变化规律。经优化后滤波器性能指标如下:中心频率为3.5 GHz,工作带宽为200 MHz,插入损耗≤1.2 dB,回波损耗≥17 dB,近端带外抑制≥25 dB,远端带外抑制≥51 dB。根据仿真模型结构参数制备得到的样品,其性能测试结果与仿真结果吻合良好。     

低损耗射频SAW滤波器的设计

采用42°Y-XLiTaO3基片,利用耦合模(COM)模型和P矩阵级联的方法对低损耗声表面波(SAW)梯形滤波器进行仿真设计。通过分析SiO2厚度对滤波器中心频率偏移的影响、建立等效电路模型对封装进行仿真,成功地设计制作了一款中心频率为1 575MHz,带外抑制大于20dB,最低插入损耗为-1.2dB的四级SAW梯形滤波器,测试结果与仿真结果相吻合。     

直接馈电的小型化微带双模带通滤波器

采用直接接触馈电的方法设计制作了一款微带结构的双模带通滤波器.该滤波器采用了分布式电容加载的双模环形谐振器,馈电时不需额外的耦合结构或阻抗变换器,在实现较大耦合量的同时,可保持谐振器的小型化.所制作的单级和两级的滤波器样品分别获得了0.6dB(在22.0%的相对带宽下)和1.1dB的最小插入损耗(在16.7%的相对带宽下)、40.0dB的带外抑制并在通带的两侧各有两个传输零点的较好测试结果,测试值与仿真值相当吻合.测试结果还表明,在得到相对较小的插入损耗的同时,也得到了优于-15.0dB的带内匹配.     

薄膜体声波滤波器结构和设计

随着无线通信设备的小型化发展,薄膜体声波谐振器(FBAR)已成为国内外研究热点.该文综述了FBAR滤波器的拓扑结构、工作原理和仿真模型,并选择梯形滤波器方案,通过ADS射频仿真软件建立起MBVD一维等效电路模型模拟其传输特性.按照全球定位系统(GPS)滤波器设计要求,设计了频带为1 530～1 590 MHz的窄带滤波器.仿真表明,增加串、并联谐振器阶数可有效提高带外抑制,而减少其面积比在进一步增加带外抑制的同时,减少了插损和器件整体面积.设计所得滤波器带宽60 MHz,带外抑制50 dB,插损3 dB.     

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。     

基于圆头谐振器的低插损带通滤波器设计

针对插入损耗高和选择性低等问题,提出了一种具有圆形开路终端的新型谐振器拓扑结构。该结构将传统的U型发夹滤波器改成V型,在V型结构的终端引入圆形开路谐振器,并在开路枝节短截线上过孔。基于新型谐振器结构设计了一款尺寸为42.9 mm×36.54 mm (0.35λ_g×0.3λ_g)的带通滤波器。该滤波器具有插入损耗低、通带可控和远端优良等优点,并且采用新型谐振器之间的交叉耦合,在近端1 GHz附近产生一个传输零点,有效优化了阻带抑制和带通滤波器的选择性。仿真结果表明,带通滤波器的中心频率为1.7 GHz, 3 dB的相对带宽为20%,最大回波损耗优于30 dB,最小插入损耗为0.20 dB,左边的带外抑制在50 dB以下,右边的带外抑制优于20 dB。实物测试结果与仿真结果基本一致,整体性能偏好,证明了该结构的可行性。     

改进型3IDT-LCR结构的低损耗小矩形系数SAW滤波器

通过理论仿真,该文研制了一种改进型的3IDT-LCR结构,并基于该结构在42°Y-X LiTaO₃压电基片上研制出一种低损耗、小矩形系数的SAW滤波器。滤波器标称频率为253.75 MHz,实测插入损耗1.05 dB,低端带外抑制接近80 dB,高端带外抑制接近65 dB,-1 dB带宽10.52 MHz,-3 dB带宽12.54 MHz,-40 dB带宽16.68 MHz,矩形系数1.33。实测结果表明,该改进型3IDT-LCR结构的SAW滤波器具备低插入损耗、小矩形系数和高带外抑制的特点。     

基于慢波特性扇形SIW的可调带通滤波器北大核心

提出了一种具有慢波特性的扇形基片集成波导谐振腔,设计了一款小型化双频带通滤波器,相较于传统SIW带通滤波器,该滤波器小型化率为64%。通过引入金属盲孔结构实现了滤波器双频带中心频率的调节,同时,采用源负载耦合结构,在带外产生了4个传输零点,实现了滤波器的高选择特性。测试结果表明,滤波器的双通带中心频率分别为4.86 GHz和6.81 GHz,3 dB带宽分别为238 MHz和212 MHz,双频带插入损耗分别优于0.9 dB和1.1 dB,与仿真结果基本一致。     

基于D-CRLH传输线的带阻滤波器

提出了一种新型对偶复合左右手传输线(Dual Composite Right/Left-handed Transmission Line,D-CRLHTL)结构,该结构单元由T型缺陷地(T-shaped defected ground structure,T-DGS)结构以及矩形贴片短截线组成,基于对传输线单元结构传输特性的全波仿真分析,设计了一款带阻滤波器。由于利用了基于T-DGS的D-CRLH传输线,该带阻滤波器具有较小的尺寸和更加陡峭的边沿特性。实验结果和仿真设计结果吻合较好:阻带中心频率为4.15GHz,插入损耗为30dB,3dB带宽为1.9GHz,20dB带宽为1.55GHz。     

一种高抑制小型化带通滤波器

该文提出了一种具有3个传输零点的高带外抑制小型化带通滤波器。通过耦合控制可在梳状线滤波器响应中引入3个传输零点。通过源/负载耦合和传输线上刻蚀的马刺线可降低带外抑制,使滤波器获得更好的性能。设计并制作了一款小型化带通滤波器实物,仿真结果表明,该文设计的滤波器工作中心频率和相对带宽分别为2.12 GHz和20%,该滤波器的回波损耗优于40 dB,插入损耗小于0.2 dB,带外抑制小于40 dB。此外,该滤波器还具有结构简单紧凑、易加工等特点,实物测试结果与仿真结果基本一致。     

C波段WLP薄膜体声波滤波器的研制

该文研制了一种晶圆级封装(WLP)的C波段薄膜体声波谐振器(FBAR)滤波器.采用一维Mason等效电路模型对谐振器进行设计,并使用H FSS对电磁封装模型进行优化,再在ADS中对滤波器进行仿真优化设计,得到阶梯型结构的FBAR滤波器.采用空腔型结构并制备出FBAR滤波器芯片,同时利用覆膜工艺对FBAR裸芯片进行覆膜和...     

一种IPD吸收式低通滤波器的设计

为解决反射信号损害系统性能的问题,提出了一种具有高带外抑制和高带外吸收的小型化吸收式低通滤波器。该滤波器通过高通通路和低通通路实现了吸收式低通滤波器;通过抑制增益支路实现了高带外抑制。利用ADS和HFSS仿真软件对滤波器结构进行优化设计,并进行了实物的加工和测试。实测结果表明:该滤波器的3 dB截止频率为4 GHz,其带内最小插入损耗0.88 dB,通带内DC到3.5 GHz的回波损耗大于20 dB,阻带回波损耗大于10 dB,10.5 GHz处的阻带抑制大于45dB,从8 GHz到30 GHz的带外抑制大于33 dB,实测结果与仿真结果有较好的吻合。该滤波器尺寸仅为1220μm×650μm×87.71μm,相比传统PCB、LTCC工艺的滤波器,体积大大缩小,符合现代射频与微波系统小型化的发展趋势。     

Ultra-Wideband Bandpass Filters Using Quarter-Wave Short-Circuited Shunt Stubs and Quarter-Wave Series Transformers

This letter introduces a topology of a very wideband filter intended for the use in ultra-wideband 3.1-10.6 GHz applications. Basic filter configuration consists of quarter-wave short-circuited stubs and quarter-wave series transformers. To improve the out-of-band rejection, a low-pass filter is added across the symmetry plane. The proposed component is fabricated in a planar microstrip configuration; however, the topology can be easily adopted for other technologies including those based on surface micromachining. The measurements have shown an insertion loss below 0.86 dB, return loss above 14 dB, group-delay variation under 0.15 ns, and the third harmonic rejection better than 16 dB.     

Miniature high selectivity filters using grounded spiral resonators

A novel miniature high selectivity filter designed using a metamaterial resonator based on four grounded spirals (ForeS) is presented. This enables extreme size reduction together with high out-of-band rejection and low insertion loss. A fabricated third-order filter has overall dimensions of lg/4 by lg/15, a 3 dB bandwidth of 3.7% at 1.63 GHz, insertion loss of 23 dB, attenuation greater than 75 dB in the lower stopband and greater than 40 dB up to 2.6 times the centre frequency.     

An HTS Wideband Filter Using Interdigital-Like Resonators at UHF Band

A wideband superconducting interdigital-like filter at UHF band has been successfully designed and fabricated. An interdigital-like resonator is proposed to realize both strong coupling and compact size. A ten-pole demonstration high temperature superconducting filter is developed with a center frequency of approximately 340 MHz and a fractional bandwidth of 26%. The measurements show that the insertion loss of the filter is less than 0.2 dB, the return loss is better than 17 dB, and the out-of-band rejection is better than 70 dB.      

基于QMSIW小型化带通滤波器设计

为有效减小X波段基片集成波导(SIW)滤波器的尺寸和插入损耗,提出了基于四分之一模基片集成波导(QMSIW)和共面波导(CPW)混合结构的小型化带通滤波器。为了提高滤波器的选择性和带外抑制,将两个CPW合并到两个级联的QMSIW谐振器中,由于两个CPW谐振器之间的耦合是电耦合,有助于产生两个传输零点,因而具有较高的选择性。该小型化滤波器尺寸仅为8.1 mm×15.4 mm,中心频率为8.7 GHz,相对带宽是16.1%,仿真测得插入损耗为0.83 dB,带外抑制大于40 dB。     

A Compact HTS Duplexer for Communication Application

A compact L-band high temperature superconducting (HTS) microstrip input duplexer for satellite communication application has been developed. The duplexer has two output channels with center frequencies at 1200 and 1250 MHz, respectively. It was fabricated on a single piece of 2-in double-sided YBCO thin film on $hbox{LaAlO}_{3}$ substrate with a dimension of 26 $times$ 42 mm. The duplexer consists of a T-junction and two bandpass filters, i.e., a ten-pole filter and an eight-pole filter for the two transmission channels, respectively. Both of the two HTS bandpass filters were specially designed to suppress the second-harmonic spurious passband. Moreover, an HTS bandstop filter is added to the duplexer to improve the out-of-band rejection at a special frequency band. As a result of the preceding special designs, in addition to a very low insertion loss (0.2 dB), considerably sharp band edge (21 dB/MHz), and good voltage standing wave ratio (better than 1.4:1), much deeper out-of-band rejection (more than 75 dB) can be realized in a much wider frequency range, i.e., up to 3 GHz, which is almost three times above the center frequency of the passbands. Although all the elements of the duplexer are integrated within a single-piece YBCO film and the layout is compact, excellent isolation (higher than 80 dB) between the two channels has still been achieved.      

低插损高频SAW滤波器的研究

采用单层膜、梯形结构基于128°YX-LiNbO3材料研究了Al电极厚度、叉指占空比、反射栅周期、拓扑结构对插损、带外抑制和矩形度的影响.为了降低带内波动和插入损耗,该文设计了一种叉指换能器(IDT)型反射栅结构,该结构对采取优化措施前后谐振器的带内最大尖峰损耗分别降低了8.84％和0.55％.最后采用此反射栅结构设计...     

Untuned low insertion loss surface leaky wave filter

The letter presents a broadband low insertion loss surface leaky wave filter using reflective multistrip couplers on an optimum cut and orientation of lithium niobate. The insertion loss has been reduced to 3?4 dB without any inductors for phase-shift networks or tuning, and the out-of-band rejection is about 23 dB. The fractional bandwidth is up to 2?5%. The out-of-band rejection can be reduced to 40 dB, when the IDTs are apodised.