一种超窄带高温超导滤波器的研制

本文介绍了一款工作于L波段的4阶超窄带高温超导滤波器,该滤波器相对带宽仅为0.5‰,插入损耗为0.3dB.给出了超窄带滤波器的拓扑结构、理论曲线、耦合矩阵、物理电路以及实际测试结果.采用蒸镀于2英寸0.5mm厚度的氧化镁(MgO)基片上的DyBa2Cu3O7双面高温超导薄膜制作,滤波器的测试曲线、模拟仿真、理论计算三者有很好的吻合,取得了较为理想的结果.     

窄带大功率高温超导滤波器的研制

本文中,我们介绍一个中心频率大约为2.015GHz,相对带宽小于0.35%,通带内回波损耗大于20dB,带外零点高度大约为-45dB,通带内插损小于0.2dB的窄带四阶双模片型高温超导滤波器.我们对该滤波器在不同输入功率下的传输特性曲线进行了测试,测试结果表明,在输入微波信号功率值为11.7W的情况下,该器件的传输特性曲线没有发生显著退化.     

WCDMA系统用窄带高温超导滤波器设计

本文在耦合矩阵的基础上设计了一个适用于WCDMA系统的12节窄带高温超导带通滤波器.滤波器基于镀有双面YBCO超导薄膜的蓝宝石基片设计,尺寸为47.54mm×18.12mm,中心频率为1940MHz,相对带宽为0.5%.滤波器采用具有非相邻耦合较弱特点的双层环带结构谐振器,抑制了不可控传输零点的出现.设计结果显示高频端和低频端的通带带边陡峭度分别达到了27.3dB/MHz和30dB/MHz,带内插损小于0.07dB,带外抑制达到100dB.本文同时讨论了交叉耦合对滤波器性能的影响.     

适用于3G移动通讯的高温超导窄带滤波器

研制了一种适用于3G移动通讯基站接收机的高温超导窄带带通滤波器.其中心频率为1949.85兆赫兹,带宽为9.7兆赫兹.为了实现极高性能,理论设计了12阶准椭圆(quasi-elliptic)函数型滤波器,引入了3对传输零点.滤波器的计算机仿真是用Sonnet软件完成的.此滤波器是在直径为2英寸、厚度约为0.5毫米的氧化镁双面超导薄膜上制作的.实测表明,达到了极高的性能要求:相对带宽0.49%,带边陡度>150dB/MHZ,带外抑制>60dB,插入损耗<0.2dB,反射损耗<-14dB.     

一种免调谐窄带高温超导滤波器

研制了一种适用于超导子系统接收机前端的免调谐窄带高温超导滤波器.其中心频率为2287 MHz,带宽为8 MHz.该高温超导滤波器采用了10阶准椭圆(quasi-elliptic)函数型结构,并引入了2对改善带边陡度的传输零点.滤波器的计算机仿真是用Sonnet软件完成的.为了达到免调谐的目的,选用了一种结构简单的双折线型谐振器.此滤波器是在直径为2英寸、厚度约为0.5mm MgO衬底的双面超导薄膜上制作的.测量结果表明,该滤波器在未经调谐的情况下具有很好的性能:相对带宽0.35%,带外抑制>80 dB,插入损耗<0.2 dB,反射损耗<-15.5dB(通带7MHz范围之内).     

适用于雷达接收系统的高温超导窄带滤波器的研制

本文介绍一种为某专用雷达设计制作的工作于L波段的高温超导窄带带通滤波器.该滤波器为10阶微带谐振器级联(CQ)滤波器,引入两个交叉偶合构成一对传输零点形成准椭圆函数传输特性来增加带外陡度.为减小非近临谐振器间寄生耦合对滤波器传输特性的影响,对所采用的谐振器结构进行了精心选择.整个滤波器制作在一块2英寸的MgO衬底YBCO片上,封装后滤波器的整体尺寸为60mm×30mm×18mm.滤波器带宽为5MHz(FBW小于0.4%).实测滤波器带边陡度超过100dB/MHz,在中心频率(3MHz以外频域抑制好于-60dB,滤波器宽带抑制好于-80dB,滤波器最小插损0.3dB.     

窄带高温超导滤波器的研制

介绍了S波段窄带高温超导滤波器的设计过程,采用仿真建模和拓扑结构优化关键技术,在不需调谐的情况下,研制成功中心频率2.1GHz,带宽6MHz,群延时起伏在4.3MHz(71.7%带宽)内达到了18.321ns,插入损耗小于0.5dB,带边陡度大于17dB/MHz,驻波比优于1.5的高温超导滤波器,有利于器件的工程化应用。     

C波段高温超导滤波器实用化研究

主要对高温超导滤波器在国内、外应用现状进行分析。在高温超导滤波器的制备上,对现流行的两种衬底MgO基片和LaA lO3基片制备的超导膜所制作的C波段高温超导滤波器的性能进行分析比较。经多次实验测试,实际曲线结果表明:MgO基片制备的超导膜所制作的C波段高温超导滤波器,比LaA lO3基片制备的超导膜所制作的C波段高温超导滤波器在性能和制备上具有优势,便于生产。对滤波器所用制冷器的制冷量进行了计算,计算结果表明可用小型制冷机。     

An ultra-narrow band eight-pole dual-mode HTS patch filter

An ultra-narrow band eight-pole dual-mode HTS patch filter was designed and fabricated. The filter is constructed by four corner-cut square patches, each of which has two resonating modes. The influence of the change of the corner-cut position on the filter response was investigated by simulations. Four small rectangle patches were added in the topology of the filter as tuning tools. By employing this unique tuning structure, the simulated filter responses and current density distributions on the patches have been greatly improved. The filter was fabricated using double sided YBCO films on a 3 in. LaAlO₃ substrate. The measured results showed satisfactory performance with center frequency 2.494 GHz, fractional bandwidth 0.2%, return loss in passband better than 16 dB, and out-of-band rejection of the filter better than 90 dB at 15 MHz away from its center frequency.     

A high-temperature superconducting filter with controllable transmission zero

This paper presents a novel microstrip feedline structure to introduce an extra and controllable transmission zero(TZ)with high rejection for a narrowband filter. This structure loads a reconfigurable capacitor at the end of the input feedline without changing the main structure of the filter. The capacitor is recognized by a 2-bit inter-digital capacitor array. The asymmetrical microstrip feedline structure is suitable for multiple-pole filter designs. A low-loss six-pole high-temperature superconducting bandpass filter with a reconfigurable TZ is designed and fabricated. The center frequency of the filter is 5.22 GHz with TZ at the lower stopband. The TZ can be tuned among four different states. The out-of-band rejection at the TZ frequency is higher than 90 d B, and the insertion loss is lower than 0.92 d B. The measured results are consistent with the simulations.     

具有宽阻带特性的6阶自均衡高温超导滤波器

本文提出了一种新颖的L型阶跃阻抗谐振器,该谐振器具有结构紧凑、抑制二次谐波能力强及易于实现电耦合及磁耦合等特点。使用该谐振器设计并制作了一款具有小型化、高选择性及宽阻带特性的6阶自均衡高温超导滤波器。测试结果表明,在70 K温度下滤波器的中心频率为1 601 MHz,3 dB带宽为24 MHz,带内回波损耗<14.87 dB,带内最大插入损耗约为0.22 dB,60%带宽范围内群时延起伏<3.13 ns,通带两侧具有一对深度的传输零点,实现了1 632~5 511 MHz范围内衰减>60 dB的宽平坦阻带。     

UHF波段宽阻带高温超导滤波器设计

在分析电容加载的微带线谐振器模型的基础上,提出一种基于叉指电容、块状电容和弓形折线电感的新颖谐振器,其第一谐频位于5.6f_0外。利用该谐振器,在28mm×12mm×0.5mm的YBCO/MgO高温超导基片上设计制作了4节超导滤波器,中心频率为500MHz,相对带宽为1%。测试结果表明该滤波器具有优异性能,带内插损小于0.3d B,反射损耗优于15d B,通带与5.6f_0处寄生通带之间的抑制度大于75d B,实现了宽阻带和高抑制度的带外抑制特性。     

绿光波段60 pm超窄带滤光片的研制

波长为532 nm的绿色激光在大气层中有较强的穿透能力,可用于自由空间光通信和激光三维测绘,为了抑制背景光的干扰,需要半功率带宽小于100 pm的光谱滤波器。因此,设计并研制了基于光学干涉薄膜的超窄带滤光片。将五氧化二钽(Ta₂O₅)和二氧化硅(SiO₂)分别作为高低折射率膜层材料,将熔石英作为基片,采用双离子束溅射沉积方法制备出所设计的光学薄膜。利用可调谐激光器和功率计测量滤光片的透射光谱,其半功率带宽为(60±2)pm,透过率达到62.6%。     

钾原子532nm可调谐超窄带光学滤波器的研究

对钾原子（4P1/2→4S1/2）态532nm 可调谐超窄带光学滤波器（T-ESFADOF）进行了理论和实验研究，建立了外电场中T-ESFADOF的理论模型，编程计算了T-ESFADOF透射谱，实验测得不同电场强度下T-ESFADOF透射谱，给出T-ESFADOF透射谱中心频率频移量随电场变化的分布曲线，并于理论计算曲线进行了比较. 关键词： 钾 线芯透射 可调谐超窄带滤波     

光子晶体反常色散超窄带滤波理论

讨论了利用由反常色散材料构成的二维（2D）光子晶体(PCs)实现超窄带滤波（PCADOF）的原理，并对铯原子蒸气6P3/2←6S1/2谱线的反常色散曲线进行了研究，讨论利用此反常色散曲线通过2D PCs实现超窄带滤波的方法和特点，研究发现这种滤光器的带宽可达到0.002nm，这将为设计一种全新的滤波器提供指导. 关键词： 反常色散 光子晶体 超窄带滤波     

高温超导滤波器的封装

高温超导滤波器的封装是影响超导滤波器性能的重要环节之一。文中详细讨论了封装盒设计应该注意的细节,避免影响超导滤波器性能的因素出现。成功地应用超声点焊的方法解决了PIN接头和高温超导滤波器电极的连接,达到了较小的接触电阻和较好的机械强度。     

Compact superconducting single-and dual-band filter design using multimode stepped-impedance resonator

This study presents two multimode stepped-impedance structures to design single-and dual-band filters. Transmission zeroes are introduced for the single-band filter by using dual-mode stepped-impedance resonators. The single-band filter with high selectivity is centered at 6.02 GHz and has a fractional bandwidth(FBW) of 25.6%. Four stubs(two low frequency and two high frequency ones) are connected to the rectangular patch in the center to construct a quadruplemode resonator. The independent conditions of the center frequencies of the high and low bands of the resonator are analyzed. A dual-band filter, which operates at 1.53 GHz and 2.44 GHz with FWBs of 12.1% and 14.1%, respectively is designed. The single-and dual-band filters are both fabricated with double-sided YBCO films and they can be used in mobile and satellite communications.     

C-band three-port tunable band-pass thin film optical filter with low polarization-sensitivity

According to the oblique incidence characteristics of thin film narrowband filter, the stack of 100 GHz DWDM four cavities angle-tuned thin film filter has been designed and optimized. The two polarization modes’ central wavelengths of the thin film filter can be centered at the same one in oblique incidence, and it has a stable tuning range of 20 nm without the phenomenon of polarization central wavelength separation. Using this kind of angle-tuned thin film filter and the polarization beam-splitters, the tuning range of the angle-tuned thin film filter can be further expanded due to the reason that it can transmit only the s-polarization light. In this paper we also developed a three-port bandpass tunable filter device with new structure, which tuning range can cover the whole C-band and its adjacent channel isolation degree is high. The experiments show that the three-port tunable filter has an effective tuning range of 33 nm, and its adjacent channel isolation degree is more than 35 dB. It has a bright application opportunity for its flexibility and effective performance.