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Speed
Posts:
3
Registered:
9/17/09


Phase shift in Simulink
Posted:
Sep 21, 2009 2:58 PM


Hello All,
I am using simulink to generate phase noise. Basically I have a since wave generator and want to introduce phase noise to this. Surprisingly I haven't found a phase shifter block in simulink. I even didnt find an Allpass filter. One other related issue I have is to generate a constant 90 degree phase shift (generate a cos signal). I do not want to introduce a new sine generator with a phase shift. I want to be able to use a single sine generator, then phase shift it by 90 degrees to get separate sine and cos signals. I am working with continuous time signals. I a constant phase shift (to generate cos signals), I even tried taking derivative (I get the 90 degrees shift but a weird gain ...which is not omega times the signal like what we expect  d(sinwt)/dt = wcoswt). I even tried to create a basic all pass filter using the transfer function block with the fn as (s1)/(s+1), still I dont get a 90 degree phase shift.
Please help me with these to concerns. 1. To introduce a constant phase shift of 90 degrees 2. To be able to generate a random pahse shift.
I can play around and get the solutions even if I get to know the solution for one of the above points. Only point to be noted is that it has to be in Simulink and not using matlab code.
This is my first post in this forum. Hope to get some positive responses.
Thanks s lot for your time and support,
With best regards, Speed



