AWR2243: When using four-chip cascade for antenna phase calibration, what is the requirement for the distance of the target to be measured from the antenna?

Hi team,

Here's an issue from the customer may need your help:

Using AWR2243 four chip cascade, self-made radar front-end board, antenna size is around 20cm.

What are the requirements for the distance of the corner reflector from the antenna when calibrating the phase with a corner reflector? Currently it is found that the phase difference between channels calibrated at different distances is large. How far is it appropriate to choose?

Could you help check this case? Thanks.

Best Regards,

Cherry