chirp configuration for adc signal

[stanlu]

hi NXP:

I place my radar board in chamber and record the ADC signal. I find the ADC signal is so noisy (Fig.1). To my knowledge, the ADC signal is smooth and a pure sine wave ( if only one corner). Do I miss something about chirp configuration?   Fig. 2 shows my chirp configuration. Thanks! 

[petervlna]

Hello,

First I would like to tell us which radar kit you are using? NXP RDK or you own desing?

What you see is normal operation.

The ADC samples will never appear as a perfect sine wave.

That is why we have to do the complex processing to retrieve the frequency information from the ADC samples.

And you can see from the screenshots that the processing is working by detecting a single object

best regards,

Peter

[stanlu]

hi Peter:

The results are from NXP reference design with 512smp x 128crp SPT.

You are right that adc samples, in practical, not a perfect sine wave. 

My adc signal, captured in chamber, is so noisy, so I wonder something I missed.

Could you provide some notes/experiences about RF setting or chirp configuration?

Thanks!

Regards, 

Stan