共查询到19条相似文献,搜索用时 171 毫秒
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介绍了L波段低温限幅器的设计和分析,并给出了测试结果.该限幅器具有插入损耗小、驻波低、限幅电平低及体积小等特点.在12K,限幅器插入损耗小于0.2dB,端口驻波比小于1.25,限幅性能较好. 相似文献
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介绍了低温低噪声放大器使用的HEMT(高迁移率晶体管)器件噪声模型的建立,对HEMT用S参数和噪声参数讲行仿直,获取适合的模型.给出了实例,放大器在低温10K工作,增益≥30dB,噪声温度≤4K. 相似文献
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Hai Ming Guangyu Xu Yu liu. Baorui Ren Jianping Xie Jingren Qian Honggao Tang 《Chinese Journal of Lasers》1993,2(5):399-404
The temperature gain dependence of an Er~(3 )-doped fiber amplifier, which is pumped by a Ti : Al_2O_3 tunable laser at 800nm band, is investigated. At liquid-nitrogen temperature of 77K, gains higher than those of 300K are obtained, but the optimum pumping wavelength has a blue shift. 相似文献
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介绍了X波段低温低噪声放大器的设计和实验结果。该放大器采用HEMT器件三级级联,频率范围为8 500MHz~8 850 MHz,在环境温度大约20K的环境下,噪声温度小于11K,输入输出回波损耗小于-25dB,功耗小于25mW,0~40GHz内无条件稳定。 相似文献
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Temperature-dependent gain and noise in fiber Raman amplifiers 总被引:2,自引:0,他引:2
An experimental investigation of the temperature dependence of the gain and noise performance of a silica-fiber Raman amplifier is described. A decrease in the Raman scattering cross section in a fiber amplifier cooled from a temperature of 300 K to 77 K was measured and found to be in agreement with theoretical values. No difference between the Raman gain coefficients at these two temperatures was observed. 相似文献
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V. I. Piddyachiy V. M. Shulga A. M. Korolev V. V. Myshenko 《International Journal of Infrared and Millimeter Waves》2005,26(9):1307-1315
The paper describes a 3mm cryogenic mixer receiver using high doping density (“room-temperature”) Schottky diodes. The measured equivalent noise temperature Teq of the diodes is 109 K at 20 K, which is much higher than the Teq of the low doping density (“cryogenic”) diodes. In spite of this, the double-sideband (DSB) noise temperature of the cryogenic receiver developed is 55 K at 110 GHz, owing to the low conversion loss of the mixer and ultra-low noise of the PHEMT IF amplifier. This is the lowest noise temperature ever reported for a Schottky diode mixer receiver. The results obtained are useful for the development of submm receivers in which high doping density Schottky diodes are used. 相似文献
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介绍了X波段极低噪声低温放大器的研制。在≤15K的环境温度下,X波段100MHz带宽内,实测放大器的等效噪声温度:≤8.8K;增益:>36dB;带内起伏:<0.4dB;输入反射损耗:<-22dB;输出反射损耗:<-20dB。它的研制成功,将可以替代进口产品满足X波段低温接收机的研制需要。 相似文献
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一种实用化实时测温系统的优化设计 总被引:11,自引:1,他引:10
基于基尔霍夫定律,利用半导体激光器及钽酸锂热释电探测器设计了一种实用化的实时测温系统。依照测温系统各主要技术指标(温度分辨力、温度的标准偏差及测温范围)与各主要技术参量(激光光源的能量、波长、放大器的带宽及光学系统的相对孔径等)之间的关系,对实时测温系统的各主要参量(激光光源的能量、光学系统的相对孔径及放大器的带宽)进行了优化设计。实验表明,在测温范围673~1473K内,温度测量的不确定度优于0.3%,分辨力优于0.4K,均符合设计要求。 相似文献
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M. Zavelani-Rossi F. Lindner C. Le Blanc G. Chériaux J.P. Chambaret 《Applied physics. B, Lasers and optics》2000,70(7):S193-S196
We have experimentally studied thermal effects in highly pumped Ti:sapphire crystals in the 140-340 K temperature range. We demonstrate that a critical temperature exists, which depends on pumping and probing conditions, below which detrimental thermal effects completely disappear. In particular, we show that in a typical high-intensity Ti:sapphire amplifier, thermal lensing and wave-front distortions can be suppressed keeping the crystal temperature lower than ~230 K. 相似文献
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为了研究低温条件下Yb:YAG放大器的增益和热特性,搭建了一套液氮冷却的低温放大器,开展了实验研究。测量了不同泵浦强度下的小信号增益以及低温和常温下的介质热致波前畸变。结果表明:低温条件下,可以用更少的泵浦能量得到高于常温的增益;常温下泵浦电流200A、脉冲宽度1200μs的小信号增益为1.59;低温下泵浦电流200A、脉冲宽度400μs的小信号增益为1.82,光光效率显著提高。自发辐射放大(ASE)问题在低温下更加显著,采用短脉冲泵浦有利于降低ASE的影响。低温的热管理效果较常温有显著提高,可以在更高的平均功率下运行。 相似文献
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介绍了8~9GHz极低噪声低温放大器的研制。在≤15K的工作温度下,实测放大器的主要性能指标如下:等效噪声温度≤7.9K;增益>31dB,带内起伏≤1dB;输入反射损耗<-21dB;输出反射损耗<-23dB。它的研制成功,实现了深空探测、天文观测等X波段宽带低温接收机的核心器件国产化。 相似文献