MMWCAS-RF-EVM: Array phase interpolation methods

Hi,

Here is the answer from systems team

The holes in the azimuth dimension of the virtual array can be avoided by using all the azimuth direction TX channels on the cascade board.

However, if a TX sequence is used that results in holes in the virtual array then there are several methods to mitigate the artifacts.

The simplistic way is to Insert Zeros at the hole locations in the virtual array. This will result in the correct angle estimation however the side-lobe levels will still be higher.

More sophisticated methods have been developed and actively being researched. TI does not have any recommendation for any particular method or algorithm. The users can look into existing literature dealing with “sparse arrays” or “array interpolation”. One example of such a paper is “Swingler, D.N. and R.S. Walker, Line-array beamforming using linear prediction for aperture interpolation and extrapolation. IEEE Transactions on Acoustics, Speech, and Signal Processing, 1989. 37(1): p. 16-30.”

Thank you

Cesar