AWR2243: MINO Antenna layout pattern in the reference document: Design Guide TIDEP-01012

Hi Vivek,

For application of cascade two AWr2243 chips, no elevation angle is considered that means the 6 TXs are positioned at the same level, in order to

get the maximum virtual RX antenna, what  the distance between the RX Array- B and RX Array-C should be spaced ? ( the space bewteen RX in the same

group is 0.5 lamda, the space between TX antenna is 2 lamdas)

Another question,

For same application, how to calculate the angular resolution in the TX beamforming mode ?

Why it said the angular resolution in these two operation mode ( TX beamforming mode and MIMO mode) are equivalent in the document:

Design Guide: TIDEP-01012

Thanks

Michael Su

Hi Vivek,

Any updaate ?

Thanks

Michael Su

Hello Michael,

If you want to use uniform antenna spacing and get good angular resolution in the azimuth angle, without any overlap antennas,  then you can have a 48 element virtual Rx array (6 Tx and 8Rx) , with all virtual Rx spaced by Lamda/2 spacing.

The angular resolution depends on the virtual receive antenna array , you can refer to some of the training material we have online for more details: https://training.ti.com/sites/default/files/docs/mmwaveSensing-FMCW-offlineviewing_4.pdf

Regards,
Vivek

Hi Vivek,

I know the angular resolution is prportional to RX antenna number,

The total RX antenna number of  the TX beamforming mode should be smaller than the MIMO mode, but why it said the  the receiver angle resolution in these two operation modes (TX beamforming mode and MIMO mode) are equivalent in the paragraph 3.4.2 of the document, TIDUEN5A ?

Thanks

Michael Su

Hi Vivek,

Any update ?

Thanks

Michael Su

Hi Vivek,

1. For application, the two AWR2243 chips are cascaded,  in order to get the more azimuth virtual antenna ( remove the overlapped antenna),

    the distance between RX array-B and RX array-C will be increased in the documen, TIDUEN5A, will it get any sid effect ? will the overlapped antenna be necessary ? what is your recommendation ?

2. In the document, TIDUEN5A, why the virtual RX antenna is 7 for elevation plane? how to calculate them?

3. For LRR application, if the azimuth FOV is +- 9 degree, the antenna configuration is 6TX + 8RX, what the azimuth angular resolution should be in the TX beamforming mode ?

Thanks

Michael Su

Hi Vivek,

Any update ?

Thanks

Michael Su

Hi Vivek,

Any comment or any update ?

Thanks

Michael Su

Hello Michael,

Please find my reply below:

1. For application, the two AWR2243 chips are cascaded,  in order to get the more azimuth virtual antenna ( remove the overlapped antenna),

    the distance between RX array-B and RX array-C will be increased in the documen, TIDUEN5A, will it get any sid effect ? will the overlapped antenna be necessary ? what is your recommendation ?

<VD> This will depend on your high level algorithms. If in your algorithms you do not use over lap antennas then its not required to have them.

2. In the document, TIDUEN5A, why the virtual RX antenna is 7 for elevation plane? how to calculate them?

<VD> In the elevation plane non-uniform antenna spacing is used to get between angular resolution. You can see the antenna spacing between the first and last elevation antenna is 3 lambda, that's how you get angular resolution of 18 deg is got.

3. For LRR application, if the azimuth FOV is +- 9 degree, the antenna configuration is 6TX + 8RX, what the azimuth angular resolution should be in the TX beamforming mode ?

<VD> As mentioned you can compute the angular resolution in your system based on antenna spacing. If you are doing beam steering also then the resolution would improve based on the angles you are steering across.

Regards,
Vivek

Hi Vivek,

About question 3, I don't still understand how to calculate the angular resolution in the stitching TX beamforming mode, if our FOV is +- 9 degree, what the angles the beam steering should be across? and how does the angular resolution be improved?

Thanks

Michael Su

Hi Micheal, 

Apologies for the delay.

The angle resolution in the stitching beamforming mode is the same as in the normal MIMO mode. Angular resolution is mainly a function of the 'aperture size' of the radar and the number of virtual antennas, which doesn't change  whether you do beamforming or MIMO. 

Assuming you are using the TI cascade board, the FoV is ~ +/- 70 degrees. You should be able to beamform across its full range.

Regards

Anil  

Hi Anil,

Sorry, I don't still understand why the stitching TX beamforming can reach the same angular resolution as the MIMO does clearly,

below is my understanding, please comment it 

As I know, the angular resolution is proportional to the RX antenna numbers, for cascading four AWR2243 chips, there will be

192 virtual RX antennas in the MIMO mode, but there will be just 16 RX antennas in the TX beamfroming mode, so in order to reach

the same angular resolution as MIMO does, the system must stitch 12 sub-beamforming ( for TI cascade board, the every across degree is about 11.67 degree) in TX beamforming mode, right ?

Thanks

Michael Su

Hello Michael,

That is correct, it will have to stitch atleast 12 different beamformings (at different angles).

regards,

Vivek