Apparatus and method for processing acquired signals for arbitrary impedance loads

A signal analysis system for processing acquired digital samples of a test signal from a device under test to represent an arbitrary load on the device under test comprising:

• a digitizing instrument having a memory for storing transfer parameters associated with the digitizing instrument and acquiring time domain digital samples of an incoming test signal;
• a test probe providing the incoming test signal to the digitizing instrument, the test probe having associated with it a memory for storing transfer parameters associated with the probe, and a controllable impedance device having selectable impedance loads selectively coupled to the device under test;
• and
• a controller having associated memory communicating with the digitizing instrument and the test probe for selectively coupling impedance loads in the controllable impedance device to the device under test and receiving the acquired time domain digital samples of the incoming test signal and converting the time domain digital samples to a spectral representation for each of the selected impedance loads, and characterizing the transfer parameters of the device under test within a spectral domain from the spectral domain representation for each selected impedance load, the controller computing load voltages (VL) from the acquired digital samples of the incoming test signal at the device under test probe point using the characterized transfer parameters of the device under test and a reflection coefficient (ΓL) representative of an arbitrary impedance load coupled to the device under test.