AWR1642: The calculation of AWR1642's phase noise and the SNR

Fucai Yan15

Part Number: AWR1642

Hi,all

I am calculating rhe SNR of AWR1642. but I find that the phase noise is so strong.

eg. the output of PA is 12dBm, the TX-RX isolation in AWR1642 is 35dB, So the leakge signal at the input of the RX chain (before LNA) is -23dBm

the phase noise of AWR1642 is about -79dBc@400kHZ, -83dBc@500kHZ, -85.94dBc@600kHZ, -88.37dBc@700kHZ,

so at the input of of the RX chain (before LNA) is -102dBm/HZ@400kHZ, -106dBm/HZ@500kHZ, -108.94dBm/HZ@600kHZ, -111.37dBm/HZ@700kHZ,

so at the input of of the RX chain (before LNA) is -56dBm~-52dBm between 400kHZ and 500kHZ, -58dBm~-56dBm between 500kHZ and 600kHZ, -61dBm~-58dBm between 600kHZ and 700kHZ

it's much stronger than the returned signal, and also stronger than the white noise.

so can anybody tell me how to improve the SNR? OR is there wrong in calculation?

my email address is fucai.yan@autofreetech.com.

Thanks

over 6 years ago

0 Cesar over 6 years ago

TI__Guru*** 147894 points

Hi,

We have contacted our hardware team and will get back to you as soon as possible

thank you
Cesar

0 aozer over 6 years ago

TI__Mastermind 29825 points

Hello Fucai,

I am currently looking into your question. It looks like you attached an image at the end of your post. Was this part of your question? It is not showing up correctly.

Regards,

adrian

0 Vivek Dham over 6 years ago in reply to aozer

TI__Guru 58035 points

Hello Fucai,
For most of the close in signal coupling of TX to RX signal the phase noise component will almost cancel out since the down conversion at the RX also happens using the same LO as the TX. Hence we get the gain of the phase noise cancellation and the SNR is mostly limited by the noise figure of the RX chain.

Regards,
Vivek

0 Fucai Yan15 over 6 years ago in reply to Vivek Dham

Prodigy 80 points

Hello,Vivek

thanks to your reply

I want to know how much dB cancelled. Is there a formula? so that I can calculate wether it below or above the white noise.

thanks.

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AWR1642: The calculation of AWR1642's phase noise and the SNR