IQ Offset characteristic change when using tx attunuator (Carrier Leakage)

Hi benjamin405,

I was able to replicate your result of the IQ offset changing with the internal attenuation, but not the initial calibration issue. I will follow up internally to see what the root cause is.

Kind Regards,
Michał

hi M_Bugajski,

On all boards we manufacture, the IQ offset measures greater than -40dB after ADRV9002 initialization.
Is there a way to improve the IQ offset below -60dB?
(As you can see in the previous question, it appears to be a local leakage problem.)

Best Regards,
benjamin405

hi,

This is the result measured at the adrv9002 output stage.
     - Frequency: 5860MHz
     - Bandwidth: 10MHz(5G V2X)
     - TX Attenuator: 0
After EVM measurement (Figure 1), the data was deleted and only the carrier was measured (Figure 2).
-55dBm was measured.
Looking at the specifications (Figure 3), Carrier Leakage is listed as -56dBm at 5800mhz.
So, considering the slight error, I believe that the -55dBm I measured satisfies the specifications.
Does it meet the specifications?

If it meets the specifications, is there a way to improve Carrier Leakage?
for example,
1. Additional offset is given externally.
2. Use products with better specifications.
(recommendation required)

Best Regards,
benjamin405

Hi benjamin405,

It looks like it does meet the specifications. I'm afraid the only way to improve that is to enable tracking calibrations, which may not work in your case.

Another way would be shift your signal away from DC, but that would require a higher sample rate.

Kind Regards,
Michał