共查询到15条相似文献,搜索用时 62 毫秒
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超导接收前端以超导滤波器和高电子迁移率晶体管(HEMT)低温放大器构成核心微波电路,其HEMT放大器在低温下拥有极低的工作噪声,但对偏置供电的要求很高,只有在特定偏置下,系统才拥有最佳的工作稳定度、高增益和低噪声。本文针对多信道超导接收前端,设计了一种多通道、模块化,带程控通讯的超导接收前端用HEMT低噪放电控组件,为设备核心射频通道提供供电、切换和远程控制。其供电偏置可调、供电纹波≤3 mV,并提供多路TTL电平接口,支持RS485数据通讯控制,便于模块化安装,在超导接收前端分机中工作状况良好。 相似文献
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介绍了3 cm低噪声接收前端的设计方法及为使其小型化应用使用了芯片GaAS MMIC混频器,并使用MWO软件对低噪声放大器电路进行了仿真。仿真数据和实测结果都表明,所设计的放大器具有较低的噪声和带内起伏,接收前端具有较高的镜像抑制度及良好的带外抑制。 相似文献
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本文叙述了用超导隧道结产生和接收声子的声子谱仪的工作原理及其测量电路.给出了用 Sn-I-Sn 声子发生器,Al-I-Al 声子检测器,硅单晶样品的声子谱仪的实验结果. 相似文献
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The ARIEL project at TRIUMF will greatly expand the variety and availability of radioactive ion beams (RIBs) (Laxdal, Nucl Inst Methods Phys Res B 204:400–409, 2003). The ARIEL front end connects the two ARIEL target stations to the existing ISAC facility to expand delivery to two and eventually three simultaneous RIB beams with up to two simultaneous accelerated beams (Laxdal et al. 2008). The low-energy beam transport lines and mass separators are designed for maximum flexibility to allow a variety of operational modes in order to optimize the radioactive ion beam delivery. A new accelerator path is conceived for high mass delivery from an EBIS charge state breeder. The front-end design utilizes the experience gained in 15 years of ISAC beam delivery. 相似文献
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E. C. Sutton W. C. Danchi P. A. Jaminet R. H. Ono 《International Journal of Infrared and Millimeter Waves》1990,11(2):133-150
In this paper we discuss the design, fabrication, and testing of a quasiparticle tunnel junction receiver for use at 345 GHz. The design employs small area Nb/Nb-oxide/PbInAu edge junctions in order to keep the device capacitance small and maintain a modest value for RNC. For optimura noise performance and beam properties the mixer is contained in a waveguide mounting structure. Our best sensitivity was obtained at 312 GHz where we measured a double sideband (DSB) noise temperature of 275 K. Noise temperatures of 400 K (DSB) or better were obtained out to 350 GHz. 相似文献
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A broadband photonic analog-to-digital converter(ADC) for X-band radar applications is proposed and experimentally demonstrated. An X-band signal with arbitrary waveform and a bandwidth up to 2 GHz can be synchronously sampled and processed due to the optical sampling structure. In the experiment, the chirp signal centered at 9 GHz with a bandwidth of 1.6 GHz is sampled and down-converted with a signal-to-noise ratio of 7.20 d B and an improved noise figure. Adopting the photonic ADC in the radar receiver and the above signal as the transmitted radar signal, an X-band inverse synthetic aperture radar system is set up, and the range and cross-range resolutions of 9.4 and 8.3 cm are obtained, respectively. 相似文献