The concept of introducing delay line in a radar system

[luckyali]

hi friends, a new issue to be discussed.
I was reading about ultra wide band radar sensors. and found a nice block diagram as follow.


the simplest thing i know is that an antenna is connected to transmitter side, transmits signals and a receiving antenna receive the signal... what is the need of a delay line in this structure. is it used for extracting phase information of the complex signal or what else it gives

 

[faneendra27]

hi,this is fani from india
radars for detecting moving targets only employs delay lines, b'coz the radar should cancel the information receving from clutters(stationary targets)
this can be done in two ways
1)butterfly method
2)delay line cancellors
1st method is not suitable for ppi scopes so we use delay line cancellation
---> the simple working of a delayline based radar is the data from receiver is delayed for one time period and applied to a subtractor circuit to which the other input is actual data with no delay.
---.since the clutter information is constant eventhough it is delayed so it cancels out,so RADAR only detects moving targets



Sorry for the lengthy answer,if u have any doubts in this u can post me:lol:

 

[luckyali]

thanks fani for your response. I wont go into such complex explaination of this. actually i have to extract some information from such setup that we used in out university lab. i can provide the recored data ploted as inphase and quadrature values...

its a gif file combination of 100 data samples at 100 delay points. if we plot both inphase and quadrature data in 3d i get such thing


actually i am confused because we studied that due to delay line the signal changes it's position along with rotation in polar form. but here i see only rotation and no position change.

apart from it. what information can we extract from these two graphs, about received signal....