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研究了在波长为0.68μm的连续激光辐照下,钇钡铜氧(YBCO)高温超导(HTS)微带线的非平衡光响应特性,并从超导体机制探索和光响应超导器件研制两个角度对实验现象进行讨论。实验观察到高温超导微带线的非平衡光响应阈值,当功率小于15 mW时,以辐射热效应为主;当功率大于15 mW时,出现非平衡光响应。该阈值的发现,是对Zeldov的“热效应”与“光子效应”同时存在理论的进一步完善,并设想了一种新型的高温超导衰减器;研究了高温超导微带线非平衡光响应的恢复时长,当激光功率为45 mW时,恢复时长约为3.5 s,分析了该时长存在的机制及其对光响应超导器件二次激光激励的影响。 相似文献
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本文在数值分析的基础上,用曲线拟合法给出了屏蔽悬置微带线的简明分析公式;并用谱域中的等效传输线法对屏蔽悬置微带线谐振器进行了理论分析,对其数值结果作了实验验证。在此基础上,研制了Q波段悬置微带线体效应振荡器,当频率为46GHz时,其最大输出频率为74mW。 相似文献
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应用矩量法,对90°拐角及其45°切角的微带线特性进行了研究。当不连续处的影响比较小的时候,例如微带线的拐角,微带线两端的微小失配将严重影响拐角处S参数的计算精度,本文提出了一种新方法对其进行处理,提高了计算结果的精确度。结果表明,选用合适切角,微带线的传输特性将会有较大改善。本文最后列表给出了不同介电常数和不同宽高比时最佳切角大小。 相似文献
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文章介绍了一种新型的耦合器—左右手组合介质定向耦合器。该耦合器的主传输线采用传统的微带线结构,而耦合电路则采用近年来引起广泛注意的左右手组合材料。左右手组合材料采用在微带线上加载集总元件变容二极管实现了耦合频率的连续移动。实验发现,当加载变容二极管的电压升高时,耦合强度随之变化且耦合频率向高频方向移动。 相似文献
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模拟开关是一种在电子工业中得到广泛使用的器件,而CMOS模拟开关,因其静态电流小,所以引起广大用户的极大兴趣。但是,CMOS模拟开关存在着寄生的可控硅锁定效应,这是一种使器件失效的模式。当开启电源时,或器件正常工作时一旦受到跳变电压、辐射感应、电源电压过冲或温度变化等因素的影响,都会导致器件的寄生可控硅效应。此可控硅被触发后,只要电源电压不立即减到足够小,即使引起该可控硅触发的外界因素消失,它仍会继续导通,以致造成器件对 相似文献
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连续工作的体布拉格光栅外腔半导体激光器的温度特性 总被引:4,自引:2,他引:4
对体布拉格光栅(VBG)作为波长选择元件的外腔半导体激光器的波长锁定进行了实验研究,报道了连续运转输出功率达43.5 W的半导体激光器阵列的体布拉格光栅波长锁定实验结果,给出了不同热沉温度下的稳定的波长锁定结果,说明采用体布拉格光栅外腔将减小半导体激光器的温控压力。实验中发现,随着注入电流的增大,输出激光功率逐渐增强,锁定的激射波长向长波长方向偏移。在输出功率为34.5 W时,波长红移约0.56 nm。这一移动与实验测量的体布拉格光栅的温度特性相吻合。连续和高占空比运行、高输出功率情况下,在器件的设计和使用时应该考虑这一效应。 相似文献
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Photoconductivity effects in polysilicon are investigated and a simple model of gap inserted between two microwave transmission lines with semiconductor layer is proposed. Then a demonstrator based on an optically controlled microwave switch is studied. The microwave switch was fabricated by using a poly silicon layer deposited on the gap in a coplanar waveguide. Test results are compared with the model. Fabrication with polysilicon has the advantage of compatibility with standard Si processing methods and may be used for applications to monolithic integration of optical and microwave waveguides on silicon. 相似文献
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《Microwave Theory and Techniques》1960,8(5):566-569
The impedance of crystal diodes is known to depend on the applied bias voltage. This has suggested the use of diodes as switching elements in the control of microwave signal transmission. In the simplest form, the diode switch consists of a transmission line which is shunted by a diode. Coaxial cables as well as waveguides have been used for the transmission lines that are shunted by point-contact and p-i-n diodes. Slab line or coaxial switches where a diode is inserted in series with the center conductor of the line have also been developed. 相似文献
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A single-picosecond GaAs photoconductive switch is used to pulse excite a microwave resonant cavity, thus generating a variety of RF (radiofrequency) waveforms with picosecond synchronization. The length of the transmission line that connects the photoconductive switch and the cavity and the strength of input/output cavity coupling elements provide for continuous variation of the frequency distribution of the generated RF power. The generation of greater than 7-kW broadband microwave bursts is demonstrated 相似文献
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Subramanyam G. Ahamed F. Biggers R. 《Microwave and Wireless Components Letters, IEEE》2005,15(11):739-741
This letter describes a ferroelectric thin-film based varactor shunt switch, for microwave and millimeterwave switching applications. Our implementation is based on a coplanar waveguide transmission line shunted by a ferroelectric varactor. The concept of switching ON and OFF is based on the dielectric tunability of the ferroelectric barium strontium titanium oxide (BST) thin-films. From experimental verification, the isolation of a switch with a varactor area of 75/spl mu/m/sup 2/ was approximately 20dB at 35GHz and the insertion loss was below 4.5dB up to 35GHz. This letter addresses the design and experimental verification of the first ferroelectric varactor shunt switch with an Si monolithic microwave integrated circuit compatible process. 相似文献
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为了提高射频标签(RFID)中基于肖特基二极管微波整流电路的效率,采用微带结构实现了一种915 MHz紧凑型的整流电路。该微波整流电路具有质量轻、尺寸小、整流输入功率动态范围大等特点,设计的仿真和实验结果显示:输入微波功率在13 dBm~22 dBm的情况下,均获得了高于60%的整流效率。通过完善改进电路,可以进一步提高整流的效率,并应用于微波无线能量传输或大型RFID的微波整流天线。 相似文献
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阵列快拍成像雷达采用阵列天线雷达成像体制,通过高速微波开关切换和高速数据采集,可以同时实现对目标的空间分辨和时间分辨,即实现雷达快拍成像,该技术在飞行器平台的辅助导航、交通监测等领域具有广阔的应用前景。阵列快拍成像雷达的特点是能够快速成像,核心技术包括微波信号收发、高速数据采集与传输、实时成像处理及阵列天线高速微波开关切换。其中,高速数据采集与传输是实现快速成像是正确成像的关键,数据缺失会导致图像散焦。本文首先分析了阵列快拍成像雷达成像原理及信号采样对数据采集与传输系统的要求;继而提出了基于光纤传输模式的数据采集与传输系统方案,系统采用四路高速AD对雷达基带信号进行采样,在FPGA中进行复数运算,通过光纤通道传送到主控计算机,系统传输速率可以达到2.5Gbps;最后,通过阵列快拍成像实验验证了系统的性能。 相似文献
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Hashimoto Y. Yorozu S. Kameda Y. Fujimaki A. Terai H. Yoshikawa N. 《Applied Superconductivity, IEEE Transactions on》2005,15(3):3814-3820
We have developed a method of designing single-flux-quantum (SFQ) logic circuits with passive gate-to-gate interconnections. Based on our method, we designed a 2/spl times/2 switch in which all the interconnections are implemented with passive transmission lines (PTLs) while short Josephson transmission line (JTL) segments are used only to adjust the signal timings. Compared with an identical switch using JTL interconnections, the switch using PTL interconnections has 45% fewer wiring junctions and requires 48% less wiring power current. The switch operated at 40 GHz with a bias margin of /spl plusmn/9.5%. 相似文献