So I'm looking at the first picture and I'm trying to figure out now the whole shielding part of the circuit works right now. The second image is the op-amp in use (INA116). The paper mentions that it's using the guard inputs to drive the shield, which will minimize signal pickup from other sources than the signal.

I understand that the guard is a wire around a high impedance node that mades sure that other nodes don't interfere with the node. Other than that I'm completely at a loss as to what to do.

I also understand how transistors work, but if anyone could clarify how the resetting actually works on this circuit that would be great. The transistors turn on when the input voltages approach common-mode input range of the amplifier.

Thank you!

edit: I tried to put the two links up as images, but it wouldn't work ;-;

  • \$\begingroup\$ Image links are broken... \$\endgroup\$
    – Adil Malik
    Jan 18 '17 at 23:24
  • \$\begingroup\$ What are the impedance requirements of your circuit? When you say "this circuit" which one. "The paper" what paper? Be specific. This question is unclear and should be closed. \$\endgroup\$
    – Voltage Spike
    Jan 18 '17 at 23:33
  • \$\begingroup\$ If you want to include the images post them as png's \$\endgroup\$
    – Voltage Spike
    Jan 18 '17 at 23:36

By buffering the shield with each input, it reduces ingress of unwanted signals and reduces the capacitance on the coaxial cable as the shield tracks the center conductor signal. Improved immunity is achieved further with triaxial or double shielded cables.

In the case of coaxial a 1MOhm drain wire provides ground reference to the source to shunt higher impedance low frequency stray fields. This is done on the outer shield for the triaxial cable on the source side.

enter image description here


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