AN INTEGRATED DC SQUID MAGNETOMETER WITH VARIABLE ADDITIONAL POSITIVE FEEDBACK
AN INTEGRATED DC SQUID MAGNETOMETER WITH VARIABLE ADDITIONAL POSITIVE FEEDBACK
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DOI：
10.1088/0953-2048/7/5/003
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发表时间：
1994-05-01
影响因子：
3.6
通讯作者：
KOCH, H
中科院分区：
文献类型：
--
作者：
DRUNG, D;KOCH, H
提出了一种易于调节的直接耦合磁力计。通过额外的正反馈 (APF)，可以实现 30 μV 的典型可用电压摆幅和 1 kHz 时低至 1.13 fT Hz-1/2 的噪声水平。只需在磁力计芯片上添加一个或两个键合连接，集成到磁力计芯片中的补偿电路就可以将 APF 增益分三步降低，幅度为 1.8 倍。这样，临界电流I0的容差从传统SQUID工作点的+/-10%扩大到+/-27%。如果另外通过等离子蚀刻修整分流电阻器，I0 的容差可以进一步增加到大约+/- 55%。
An easily adjustable direct-coupled magnetometer is presented. A typical usable voltage swing of 30 muV and noise levels of down to 1.13 fT Hz-1/2 at 1 kHz have been achieved with additional positive feedback (APF). A compensation circuit integrated into the magnetometer chip allows the reduction of APF gain in three steps within a factor of 1.8, by simply adding one or two bond connections on the magnetometer chip. In this way the tolerance of the critical current I0 is enlarged from +/- 10% to +/- 27% at the traditional SQUID working point. If additionally the shunt resistors are trimmed by plasma etching the tolerance of I0 can be increased further to about +/- 55%.