Ka波段低温低噪声放大器的设计

介绍了Ka波段低温低噪声放大器的设计和试验结果。在物理温度20K的环境下,在4GHz频率范围内,噪声温度小于27K,增益大于18.5d B。     

S波段低温低噪声放大器的研制

介绍了基于ADS仿真的低噪声放大器的设计与制作方法;重点研究了LNA的直流偏置、稳定性分析、匹配设计、版图制作和调试;提出了源级负反馈和栅极加并联阻抗的方法来实现了电路全频段稳定和低温正常工作。采用ATF-34143制作了中心频率在2.25的低噪声放大器,在77K温度下,该放大器带内输入输出驻波比小于1.2,增益达到23dB,噪声系数为0.24dB。     

X波段低温低噪声放大器的研制

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。     

S波段低温低噪声放大器

中介绍了S波段低温低噪声放大器的研制.在15K左右的环境温度下,300MHz带宽内,实测放大器的等效噪声温度≤4.6K,增益≥35dB,增益平坦度≤1.0clB,输入、输出回波损耗≤-20dB.它已经成功运用于射电天文等领域.     

具有陷波电路结构的P波段低温低噪声放大器

该文的工作是设计和制作了一种具有陷波电路结构的P波段低温低噪声放大器。在低温75K环境下,工作频段为250-350MHz的范围内,该低温低噪声放大器具有优异的性能,噪声系数小于0.4dB,增益为14.4dB,增益平坦度小于0.05dB,输入反射损耗S11<-20dB,输出反射损耗S22<-20dB。同时在工作频段外的高温超导滤波器寄生通带内,该低温低噪声放大器成功实现了传输陷波响应,加强了系统对前端高温超导滤波器产生的寄生通带的衰减和抑制。     

Ka频段低温限幅放大器设计

通过对核心低温器件进行低温参数测试的方式进行选型和设计,制作了一款MMIC集成结构的Ka频段低温限幅放大器,测试结果表明,在物理环境温度20 K下,工作频带32 GHz~38 GHz范围内,其噪声温度T_e≤73 K,增益≥16.8 dB,限幅耐功率电平≥2 W,能够有效提升接收机系统灵敏度和抗烧毁能力。     

低温低噪声放大器的发展概况及其结构设计综述

介绍了低温低噪声放大器的研制历史、现状及应用情况 ,举例分析了在该类放大器的结构设计中需要解决的关键技术 ,对军事和民用装备的有关领域有参考作用。     

低温低噪声放大器测试平台的结构设计

本文介绍了低温低噪声放大器的应用情况,以及确保它正常工作所需的结构设计方面的一些问题。     

低温低噪声放大器的预修正设计与实现

本文给出了一种设计低温LNA的预修正设计方法.首先按照LNA常温设计方法设计低温LNA,然后,测量出低温情况下LNA的S参数.忽略匹配网络常低温下的变化,利用软件抠除输入输出匹配网络对S参数的影响.然后,利用这个低温参数模型优化匹配网络使低温LNA各项性能均达到设计要求.最后利用这种方法设计并实现了一款频率范围0.8GHz～2.4GHz驻波小于1.5,增益大于23dB,纹波小于1,噪声小于0.5dB的低温低噪声放大器.     

X波段极低噪声低温放大器

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。     

The development of a simplified cross-bar mixer operating at Ka-band

Many receivers operating at millimetre wavelengths utilise a frequency downconverter as their first stage. A rugged, low-conversion loss and simplified cross-bar mixer operating at the atmospheric window centered at 33 GHz was designed, developed and tested as a forerunner to mixers operating at atmospheric windows centred at higher frequencies. The cross-bar mixer exhibits a conversion loss of less than 5 dB over a bandwidth of 2 GHz. Design and optimisation procedures of the mixer are outlined.     

The development of nonradiative dielectric waveguide transmitting front-end in Ka-band

The operating theory,design method and experimental results of the nonradiative dielectric waveguide (NRD-guide) transmitting front-end in millimeter wave band are related in details in this paper. As a kind of dielectric waveguide,the NRD-guide possesses fine transmission performances, and it can be used to fabricate the millimeter wave hyterodyne integrated circuits. The two kinds NRD-guide transmitting front-ends substantiated in the paper, the voltage controlling oscillator(VCO) and twin-Gunn-diode power-combiner,have very similar structures to each other and possess compact sizes, fine machinery and electric performances.For the VCO front-end in Ka-band, the frequency modulation band is greater than 150MHz, the output power is larger than 20mW.For the power-combiner, the output power is larger than 40mW,the combination efficiency is better than 90%,the frequency stabilization reaches 1.68×10^–5. Combined with the receiving front-end reported before,the transmitter and receiver can be composed to a dielectric waveguide R/T module to be applied in some millimeter wave sub-systems.     

L波段低温限幅器的研制

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.     

Progress in the development of cryogenic detectors for GNO

An improvement of the statistical and systematic uncertainty beyond the level achieved in GALLEX is an essential prerequisite for GNO. As major contributions to these errors are associated with the detection of the EC-decay of ⁷¹Ge in miniaturized gas counters, low temperature calorimetric detectors might provide a promising alternative for a later phase of GNO. We report first results achieved in measurements of the EC-decaying isotopes ⁷¹Ge and ³⁷Ar with cryogenic calorimeters.     

低温贮运设备的关键技术及发展趋势展望

低温贮运设备经历堆积绝热、高真空绝热、真空粉末(纤维)绝热和高真空多层绝热四个阶段,形式有低温贮罐、低温运输车、低温铁路罐车和船载低温罐等,目前高真空多层绝热凭借优异的绝热性能被广泛采用。回顾了低温贮运设备的发展历程,对低温贮运设备的抽真空工艺、支撑结构、无损贮存和制造过程质量控制等关键技术进行了阐述并提出了发展方向。对低温贮运设备未来的发展趋势进行了展望。     

Ka波段宽带谐波抑制定向耦合器

为解决传统分支线定向耦合器带宽较窄,且应用到线性化器等微波元件中时受谐波信号影响较大的问题,提出了一个宽带且带有谐波抑制功能的定向耦合器。该定向耦合器在双支节定向耦合器的基础上增加一个支节,可有效地提高定向耦合器的带宽,同时将其传输线支节替换为低通滤波结构,以实现对高次谐波抑制的作用。仿真结果表明,该定向耦合器的反射系数和隔离度均小于-15 dB,传输损耗小于3.8 dB,波动范围0.5 dB,相位差为90°且与双支节耦合器相比增加1 GHz带宽。满足耦合器的设计指标,可应用到微波元件中,提高微波元件的性能。     

Thermistor controlled gunn oscillator at Ka-band

Frequency drift of Gunn oscillators is a major cause of concern in most of the Millimeter wave communication systems. This paper describes a simple and cost effective technique to arrest the frequency drift of a Ka band Gunn oscillator within 15 MHz for the operating temperature range of 0°C to 60°C as against a typical drift of about 50 to 100 MHz for free running Gunn oscillator for the same temperature range. At the ambient, the oscillator remains within ±1 MHz from switching on to stabilization. The temperature variation is sensed with a small thermistor bead placed close to the diode and a correction voltage is applied to the bias to compensate for the frequency drift. This compensation circuit also takes into account the non-linear behaviour of the thermistor and the Gunn oscillator with the temperature.