MMWCAS-RF-EVM: applying start frequency variation to the chirps

Hello Mostafa,

1. Yes, it is possible to apply start frequency dither for individual chirps in a frame. You can refer to the parameter "Start Freq Var (MHz)" in the ChirpConfig API.

To see the valid limits, please refer to mmWave ICD document. and Since it is an offset, it can take only positive values.

Please refer to the below APIs in the ICD :

AWR_CHIRP_CONF_SET_SB

AWR_PROFILE_CONF_SB

2. This question is not quite clear to me. Do you mean "which chip is used to change the frequency of the chirps"?

If yes, then the device which is selected on the right toolbaar (out of the 4 devices) will be the one whose chirps will experience a start frequency dither.

Regards,

Ishita 

Hi Ishita, 

Thank you for your quick reply. I actually wanted to know which chirp will be used for mixing the chirps at the receivers. For instance, if the master chip has all chirps with zero start frequency offset and chip #2 has all chirps with df frequency offset, then which chirp will be used to downconvert the signal at the chip #2 receivers? Is it the master chirp or the chirp of chip #2 itself? 

Best, 

Mostafa 

Hello Mostafa,

Sorry for the confusion, I guess I was wrong in my previous response (in hurry, I didn't realize we're talking about cascade here). Sincere apologies for that.

Section 5.2 of the below app note accurately describes your concern :

AWR2243 Cascade

As stated, in cascaded devices, all the timing and frequency parameters are expected to be configured exactly similar for all devices through the profile configuration API. And since it is only the master/primary device which generates the LO signal, frequency dithering parameters will have no meaning in the slave/secondary devices.

Again, extremely sorry for the confusion.

Let me know if you need any more information or clarification.

Regards,

Ishita