About MyRaidRF-1 Phase Imbalance Error

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1

Hello Everyone, I found there are phase imbalance for LMS6002DFN, and the phase error is different when signal is changed. Could anyone tell me what is the reason?
Please look the following picture:

2

And Could anyone tell me how to correct it?
Thanks.

3

By the way, Basic info of our system is: use 2 MyRaidRF-1 boards for our TD-LTE system platform(For Indoor application), CPRI interface and DSP board is involved, besides, PCIE，SATA, SFP fiber is involved.

4

Now I think I know why it happened for different frequency signal, they experience same delay but because of different freq, the phase pass is different.

Now could anyone teach me how to correct the I Q delay imbalance?

5

Hello Lex,

Just shift in phase/gain I or Q branch till you get perfect orthogonality between them.

Andrew

6

Thank you andrew, do you have the measurement delay value of different frequency CW signal?

7

Lex,

There are data provided by Lime about IQ calibration:

https://groups.google.com/forum/#!topic/limemicro-opensource/DEduAeZJcjM

Andrew