AWR6843: I would like to inquire about the issue of short-range detection of the AWR6843 antenna

HI, there:

The immediate close-in peak usually comes from the TX to RX coupling.   From the figure, it seems that your board has 10+ more dB in coupling.   For the second peak around 0.7~0.8m, I am not sure, do you have any object around that range?   For your 2m target, you EVM shows about 5dB higher gain.  Is that mean your antenna has higher gain?  Assume you have run RF calibration in the target code. 

Best,

Zigang

Hi~

The antenna was designed exactly like EVM, so there was no RF calibration.

We measured it in the same environment. 

2 meters is a wall and there was nothing at a distance of 1 meter. 

If close distance is antenna coupling problem, what problem is 1m distance detected?

HI, 

Maybe you do not have anything in front of radar around 1m.  But do you have any ceiling or floor that is about 1m away?

Best,

Zigang 

You mean the ceiling or floor was measured in the antenna range, right?
I'll measure it again.

When I measured it again, it was not detected around 1m.
So should I increase the distance between Tx1 and Rx4 or apply GND to solve the coupling problem?

Great!  So reduce the coupling will be your main concern now, correct?  In that case, I will need to bring help from our hardware design expert. 

Best,

Zigang 

Hi,

       From the snap shared by you the structure and surrounding components(especially the big decaps) appear to very different.

Even if you have taken the antenna structure from the EVM, there are lot of other things like PCB material, stack up,  etching tolerances, etc, which are absolutely critical for the expected functionality of board.

Additionally, what about the ball to pcb pad to rf trace section was that also same or simulated to affirm the expected performance?

Regards