phase advancing of a signal by 90 degrees

I want to sense a signal, and advance the phase of the signal by -90 degrees, keeping the magnitude of the signal same (in MATLAB Simulink). Please help.

I am attaching a simulation, where i tried to extract the magnitude and phase of the signal and added -90 °, and re-convert it. But it is not working.

Answer 1

[Walter Roberson]

Multiply the signal by -1i .

You can either do that by a multiplication, or by taking

complex(imag(TheSignal), -real(TheSignal))

[priya]

Isn't it giving a 180 degrees phase change? I want to shift the signal by 90 degrees.

[Walter Roberson]

https://www.electronics-tutorials.ws/accircuits/complex-numbers.html

270 degree rotation is which is

[priya]

but it still can't be shifted by 90 degrees

[Walter Roberson]

"degree to radian1" is an odd block name for that purpose...

That looks like a gain block, and that looks like a plain sine wave that is not marked as being complex. You should probably use a https://www.mathworks.com/help/simulink/slref/realimagtocomplex.html block so simulink knows you are forcing complex. I would suggest a math block to take the negative, and feed that into the imaginary portion of the realimagtocomplex block and feed 0 in as the real part. And remember to scope the real and imaginary parts, not the absolute value of the signal

[priya]

still.. i dont get it.

[priya]

i want to get the final output like the dashed line (input is the solid line)

[Walter Roberson]

That is not changing the phase of the signal by 90 degrees: that is putting in a delay of either 1/4 or 3/4 of the period.

Clock times frequency times 2 π, minus phase, sine thereof.

[priya]

Thanks for your efforts, Actually i want to sense a signal (that will be of sinusoidal nature) and phase shift it by -90 degress. but that is still not done.