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- Jan 1, 1970
- 0
Hi
I am trying to obtain the IDS versus VDS of a MESFET at cold
temperatures. I have made a small circuit with a drain resistor 200
ohms (common source) and some bias elements. I have normal stranded
wires connected for Gate bias,. drain bias and 1 to measure the drain
voltage. Theoritically and from other publications the drain current
values for Liquid nitrogen temperatures should be more than at room
temperature. However, i am seeing a reverse trend.
For a given applied Gate bias the drain currents are smaller for a
particular VDS. I am not sure why is that. The only thing i can think
of is the thermo couple affect - is it messing my readings. My wires
are running from room temperature power supplies to the preamp which is
dipped inside liquid nitrogen.
Please help, i have very less experience in cryogenic measurements.
Thank you
I am trying to obtain the IDS versus VDS of a MESFET at cold
temperatures. I have made a small circuit with a drain resistor 200
ohms (common source) and some bias elements. I have normal stranded
wires connected for Gate bias,. drain bias and 1 to measure the drain
voltage. Theoritically and from other publications the drain current
values for Liquid nitrogen temperatures should be more than at room
temperature. However, i am seeing a reverse trend.
For a given applied Gate bias the drain currents are smaller for a
particular VDS. I am not sure why is that. The only thing i can think
of is the thermo couple affect - is it messing my readings. My wires
are running from room temperature power supplies to the preamp which is
dipped inside liquid nitrogen.
Please help, i have very less experience in cryogenic measurements.
Thank you