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Philippa Young
Designing an Analogue Low Pass Filter System for a Quantum Ion Trap.
Testing
To test the filters an oscilloscope and a frequency generator are needed. The oscilloscope is used to first measure the voltage out from the frequency generator each time. This should remain constant; in this case around 3V.
The filter is then connected into the loop so that the Vin comes from the frequency generator, and Vout goes to the scope.
The voltage out is measured on the scope as the frequency is increased in order to obtain enough data to plot a graph.
The following pages show the acquired data and a graph of the response from Excel.
Filter 34
Filter 70
Filter 72
Filter 84
Filter 94
These results show that all the filters perform to the same standard. All six filters have less than 10-4 of the signal remaining at 100 kHz as required by the specification.