I came across this citcuit but i dont know what does it do?
second part of image is understandable , but first section i dont know

phase macro and phase polo are just the lable, so it might be giving single phase from three phase but im confuse with circuitry.
Any help?

 

It's combining three signals (R, B, Y) adjusting for phase and amplitude.

 

thanks for the reply,
do you have any source or link or book you can recommend to let me see it's usage?