高温超导带通滤波器

本文报道用LaAlO_3衬底GdBa_2Cu_3O_1高温超导薄膜研制的四极平行耦合带通滤波器。在77K测试,结果为:中心频率为8.96GHz,带内插入损耗为0.54dB,带宽为500MHz。文中还讨论了设计制作高性能微带滤波器应注意的问题。     

平行耦合微带滤波器设计与实现

本文的目标是设计制作一个中心频率为3．0GHz，通带200MHz。插入损耗小于3．5dB的微带带通滤波器。本文首先阐述了微带滤波器的工作原理、设计方法，接着介绍了该微带滤波器的设计过程。最后给出实物测试结果。     

双模微带三角形贴片滤波器的改进设计

双模微带谐振器用于微波滤波器设计时具有独特的优点。近年来出现了一些由双模微带三角形贴片谐振器设计的滤波器,这类滤波器结构简单,尺寸小,通带损耗小,功率容限大。但是也都存在一些共同缺陷,诸如带外抑制能力较差,容易受到高次谐波分量的干扰等等。本文在原有设计的基础上,提出了新的改进措施。实验和测量结果均表明,改进后的滤波器克服了原有的缺陷,性能得到很大改善,可以得到广泛应用,特别在高温超导(HTS)工艺中具有更加诱人的应用前景。     

高温超导带通滤波器

本文报道用ＬａＡｌＯ２衬底ＧｄＢａ２Ｃｕ３Ｏ７高温超导薄膜研制的四极平行耦合带通滤波器。在７７Ｋ测试，结果为：中心频率为８．９６ＧＨｚ，带内插入损耗为０．５４ｄＢ，带宽为５００ＭＨｚ。文中还讨论了设计制作高性能微带滤波器应注意的问题。     

第三代移动通信用高温超导滤波器的研制

简单介绍了高温超导滤波器系统的构成和性能特点,根据第三代移动通信的技术要求,设计开发了两种类型的高温超导滤波器,针对频分双工的CDMA2000标准,开发了基于自均衡结构的线性相位超导滤波器,滤波器中心频率为830 MHz,带宽为10MHz,其65%带宽内的群时延波动小于±10 ns,带边陡度超过35 dB/MHz.针对时分双工的TD-SCDMA标准,开发了基于双模结构的大功率超导滤波器,滤波器的中心频率为2017.5 MHz,带宽为15MHz,其功率承载能力达到10W以上.     

双模微带三角形贴片滤波器的改进设计

双模微带谐振器用于微波滤波器设计时具有独特的优点。近年来出现了一些由双模微带三角形贴片谐振器设计的滤波器,这类滤波器结构简单、尺寸小、通带损耗小、功率容限大。在传统的双模微带三角形带通滤波器的基础上,利用分形结构提出一种新型的双模微带三角形带通滤波器,并对此结构的性能进行了分析和研究。实验和测量结果表明,改进后的滤波器在保持原有滤波器性能的基础上,由于引入了分形结构使滤波器的尺寸更加紧凑、有更好的带外抑制能力。仿真和实测结果基本吻合。     

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。     

自均衡双通带微带滤波器综合与设计

 本文介绍了一种利用复传输零点设计自均衡双通带滤波器的方法,并用开环微带谐振器实现该滤波器电路.利用全波仿真软件,设计了一个12阶双通带自均衡高温超导薄膜微带滤波器.仿真结果显示该滤波器两个通带分别为2.631~2.679GHz,2.781~2.829GHz,阻带为2.681~2.779GHz,平坦的群时延占整个带宽60%以上.     

MgB2超导薄膜半开环结构微带滤波器设计

采用MgB2超导薄膜材料设计了一个L频段的滤波器.该滤波器采用半开环结构微带谐振腔,产生准椭圆函数响应.滤波器带宽为61 MHz,中心频率为1.75 GHz,带内波纹小于0.1 dB,回波损耗大于18 dB.针对微带滤波器设计过程中出现的中心频率偏移、回波损耗过大等问题提出了解决方法.     

一种RBF神经网络辅助设计的新型微带双模滤波器

通过引入弯折型马刺线,提出了一种新型微带双模滤波器。该结构降低了传统微带双模滤波器的耦合损耗,减小了滤波器尺寸,并具有良好的可调节带通特性。给出了该滤波器的模式激励与耦合工作机理的物理解释,并提出结合RBF神经网络方法,外推滤波器结构参数的设计方法。该滤波器实验结果与预测结果吻合良好。     

Superconducting quasi-lumped element filter on R-plane sapphire

Recent advancement in superconducting microwave technology has led to commercial deployment of high-temperature superconducting (HTS) subsystems for wireless communication applications. Commercialization of the HTS thin-film devices lies within, among other factors, the quality and consistency of the HTS film, as well as the overall cost and performance of the subsystem. In this paper, we present the design and performance of a quasi-lumped element filter on sapphire substrate. Centered at 1857 MHz with 0.8% fractional bandwidth, the six-pole Chebyshev filter has an insertion loss of less than 0.2 dB at 60 K, which translated into a realized unload Q of 35000. This is an important step toward the commercialization of superconducting devices using industrial standard wafers. With the continuous improvement of the HTS film quality, YBCO film on sapphire could be an answer to the future     

Design and Performance of an Ultra-Narrowband Superconducting Filter at UHF Band

A stepped impedance spiral resonator suitable for high-temperature superconducting (HTS) filter with bandwidth narrower than 0.5% is presented. An eight-pole demonstration HTS filter is developed with a central frequency of 650 MHz and a bandwidth of 0.3%. The measurements show that the insertion loss is less than 0.3 dB, and the return loss is better than 16 dB. The filter has out-of-band rejections of 65 dB at 2 MHz below the passband and 80 dB at 2 MHz above the passband, respectively.     

CDMA系统用高性能高温超导滤波器的研制

本文研制了用于CDMA移动通信系统的高性能高温超导滤波器。该滤波器中心频率为832MHz,带宽为6MHz（相对带宽为0.72%）。为了实现结构紧凑的滤波器,采用了线条宽度和间距均为80μm的双螺旋形谐振器,在MgO基片上实现的12节滤波器尺寸仅为41.4mm×14mm。对滤波器的敏感度分析结果表明,该滤波器的频率响应特性对基片参数和仿真Cell尺寸的变化不敏感,具有较高仿真准确度。滤波器制备采用了高精度光刻和离子束刻蚀工艺,实际测试结果与仿真结果吻合得很好,并且无需调谐即表现出良好性能,插入损耗小于0.36dB,反射损耗大于15.6dB,带外抑制大于100dB。     

Adjustable multilayer HTS filters

An adjustable multilayer high-temperature superconductor (HTS) bandpass filter has been fabricated. Taped comb-line filters with multilayer structures were designed, YBa₂Cu₃O_7-δ (YBCO) thin films deposited on LaAlO₃ were used to construct the packaged multilayer HTS filter. The electrical length of the resonators in the filter was smaller than a quarter-wave length. The frequency responses of the filter were measured at liquid nitrogen temperature 77 K. The insertion loss of the packaged filter was determined to be less than 0.5 dB. By mechanically adjusting the multilayer structure, the center frequencies of the filter changed from 1.78 to 1.92 GHz, and the variations of the bandwidth from 60 to 150 MHz were also obtained     

基于128°YX-LiNbO3压电材料的DMS滤波器设计

设计了一种基于128°YX-LiNbO₃压电材料的双模耦合声表面波(DMS)滤波器。采用耦合模(COM)模型进行理论分析,得到DMS滤波器的二维器件模型,再采用COMSOL进行二维器件仿真分析,得到单级DMS滤波器。为了消除该DMS滤波器在其低端近阻带附近出现的肩峰,该文提出将DMS滤波器表面覆盖一层SiO₂薄膜,形成温度补偿结构,从而解决低端近阻带附近的肩峰。结果表明,设计的DMS滤波器的中心频率为891.0 MHz,最小插入损耗为-1.29 dB,1 dB带宽为34.0 MHz,相对带宽为3.8%,矩形系数为2.94,带外抑制约为-20 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.      

HTS coplanar meander-line resonator filters with a suppressed slot-line mode

The design and experimental results of a four-pole coplanar waveguide (CPW) quasi-elliptic filter using high-temperature superconductor (HTS) films are presented. Quarter-wavelength meander-line resonators are used in the filter topology. Although the resonators are aligned in two lines, no bond-wire bridges are required to balance the ground planes in the design and measurement. The slot-line mode of the filter was shifted to be higher than its third harmonic. The filter is highly miniaturized and the performance is significantly improved by the use of superconductors. The main circuit of the filter only has an area of about 6.6 mm /spl times/ 2.4 mm on a magnesium oxide substrate, coated with 600-nm-thick YBCO HTS thin film on single side of the substrate. The 3-dB bandwidth is about 1.6% centered at 2.95 GHz. The performance measured at 30 K, without any tuning, gives an insertion loss of better than 0.4 dB and a return loss of about 12 dB in the passband. The first spurious mode is about triple the center frequency.     

超宽带低损耗SAW滤波器的优化设计

该文介绍了基于大机电耦合系数乐甫波模式的超宽带低损耗声表滤波器的开发,基底为15°YX-LiNbO3晶体和铜电极。设计采用修正的耦合模模型进行精确仿真以及模拟退火算法进行谐振器参数的优化。通过假指电极宽度/长度加权来抑制横向模式谐振造成的寄生响应,通过在滤波器表面涂覆黏性膜来有效抑制瑞利波模式造成的寄生凹坑,最终制作出一款中心频率约620 MHz,插损0.94 dB,-1 dB相对带宽14.9%,-3 dB相对带宽18.3%,带外抑制大于40 dB性能较优良的器件。     

"风云二号B星"原始云图数据解调技术

“风云二号B星”气象卫星的原始云图数据是时分复用的突发载波调制信号,本文就其特殊的预告码对于载波恢复电路捕捉性能的影响进行了分析,并对具有不同类型和带宽的低通滤波器的载波恢复电路性能进行了仿真。结果表明,理论上最优的积分泄放检测滤波器将可能使突发载波的捕获无法实现。论文针对不同滤波器带宽的误码率性能进行了仿真,结果表明基带5MHz带宽的FIR滤波器在突发载波模式下,可以获得比4MHz带宽更好的误码率性能。最后给出了一种经过优化的载波恢复和检测电路,并成功应用于工程实践中。