I want to test GPS receiver chip at analogue part. impedance of input RF is 50ohm, but impedance of output IF is not 50ohm and is about 1M ohm. I am not sure if E4440+Noise Source is suitable for this case. Should I add a impedance match part to change outnput impedance to 50ohm?? Could you give me some advice?? Thanks!!
Depending on the DUT gain and output Voltage, either a passive or active probe could be used to convert the impedance from 1MOhm to 50 Ohms. Calibrate without the probe in 50 Ohms at IF frequency range, then connect the DUT and probe combination. The loss of the probe (if it has loss) can be compensated under the loss comp menu. The 85024A probe should work well for single-ended devices with sufficient gain. This active probe has approximately 0dB gain from 300kHz to 3 GHz which should work at your IF frequency range. Differential probes such as the U1818A should work for differential IF outputs. Please feed back to the forum how this works for you!
Regards -