I'm looking for help/advice designing an impedance matching circuit. I am trying to measure noise (PSD) across a resistor, I have a 500 Ohm resistor that i need to match to the input of a preamplifier with an input impedance of 100 MOhm.

This would be quite easy if I only wanted it to be matched for one frequency but I need it to be matched for a wide range of frequencies, specifically 0-100kHz.

I have found some information which states that broadband matching requires 4 reactance networks, unfortunately it doesn't give any information on how to calculate their magnitudes.

Any advice on this matter would be most appreciated.

Thanks,

Karl