Electromagnetic-Wave Sensitivity of HEMT at the Cryogenic Temperature

HEMT 在低温下的电磁波灵敏度

基本信息

批准号：
63550033
负责人：
KASUGA Takashi
金额：
$ 1.22万
依托单位：
National Astronomical Observatory
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550033/
关键词：
HEMT Cryogenic Temperature Microwave Millimeter-wave DX center Light Amplifier Mixer 低雑音アンプ

项目摘要

There are some problems when the microwave HEMT amplifiers are cooled down to the cryogenic temperature. The experiment using 23GHz HEMT amplifier in the last year shows that noise temperature becomes lower and problems are nearly solved by applying red LED light to the HEMT chip. And We claimed that all chips in the amplifier must be illuminated for better stability and resetability and no hysteresis.In this year we developed the cooted millimeter-wave HEMT mixer. This mixer has only one HEMT as a key component, and temperature and illumination effects are clearly examined. The input signal (43GHz) is fed through waveguide/antenna and stripline to a gate electrode and the local power (41.6GHz) through coaxial cable and stripline to a drain electrode. The IF output (1.4GHz) from the drain electrode is amplified by the ultra-low noise amplifier. This "drain" mixer can have a gain theoretically. The light from a room-temperature LED is fed through a optical-fiber. The whole is cooted down to the cryogenic temperature.The cryogenically cooled HEMT mixer is thought to be a good candidate as a frontend of millimeter-wave radio telescopes. This experiment is the first one in the world. The mixer conversion loss 3.2 dB which value is lower than that of diode mixer was obtained at the room temperature. Large effects of cooting and illumination will be obtained.HEMT used in the millimeter-wave region is very preliminary, and electric parameters between chips/lots change. Now we search the best matching circuit for each chip and mixer.

当微波HEMT放大器冷却至低温温度时，存在一些问题。去年使用23GHz HEMT放大器的实验表明，通过将红色LED灯涂在Hemt芯片中，噪声温度变得较低，并且几乎解决了问题。我们声称，放大器中的所有芯片都必须照亮，以提高稳定性和可重复性，并且没有磁滞性。今年，我们开发了同时的毫米波Hemt混合器。该混合器只有一个HEMT作为关键组成部分，并且清楚地检查了温度和照明效应。输入信号（43GHz）通过波导/天线和条带馈送到栅极电极，并通过同轴电缆和条线到达排水电极的局部电极（41.6GHz）。从排水电极中的IF输出（1.4GHz）通过超低噪声放大器扩增。这种“排水”混合器可以从理论上获得增益。室温LED的光通过光纤喂食。整体被凝固至低温温度。低温冷却的Hemt混合器被认为是毫米波射电望远镜的前端的好候选者。该实验是世界上的第一个实验。在室温下获得了混合器转换损耗3.2 dB，其值低于二极管混合器的值。将获得固定和照明的很大影响。在毫米波区域中使用的hemt非常初步，芯片/批次变化之间的电参数。现在，我们为每个芯片和混音器搜索最佳匹配电路。