Test Setup: As per attached figure.
IP3 measurement:
F1 = 2MHz
F2 = 2.9MHz
Power combiner isolation: 6dB
Attenuation = 20dB
Input power to DUT =-20dB
Based on current setup, after optimising the attenuation settings on the MXA, I get about 35dBm OIP3 using a thru. ( I would need to get to get the test setup to be able to measure >40dBm)
I have no problem when measuring about 10MHz. Could this be due to the PSG is having more harmonics at this low frequency?
My question is if you have any suggestions to improve my test setup?
IP3 measurement:
F1 = 2MHz
F2 = 2.9MHz
Power combiner isolation: 6dB
Attenuation = 20dB
Input power to DUT =-20dB
Based on current setup, after optimising the attenuation settings on the MXA, I get about 35dBm OIP3 using a thru. ( I would need to get to get the test setup to be able to measure >40dBm)
I have no problem when measuring about 10MHz. Could this be due to the PSG is having more harmonics at this low frequency?
My question is if you have any suggestions to improve my test setup?
You might do some tests to see if the OIP3 is limited by the source or the SA. Add 10 dB attenuation to the SA, and see if the OIP3 improves; use a lower RBW if the noise gets too bad. If it does not improve you know you have source problem; if it does improve you have an SA problem.