Tell me more ×
Signal Processing Stack Exchange is a question and answer site for practitioners of the art and science of signal, image and video processing. It's 100% free, no registration required.
up vote 0 down vote favorite

I'm playing with Python & numpy to filter audio. It is relatively straightforward to design and us low-high-bandpass/stop FIR and IIR filters, stuff can be done in a couple of lines.

I'm implementing a small software defined radio software, and I need an all-pass filter that has 90 degrees phase shift everywhere, and is flat (as much as possible).

Unfortunately I was unable to find any quick solution for this.

Please share your thoughts on this.

Thank you,

Tamás.

share|improve this question
Welcome to DSP.stackexchange. This site can help you if you need to answer a question of how or why something works, or do not understand a concept, help you devise an algorithm from the domain if signal processing. What you're looking for is more programming - maybe you should flag your own question and request it be moved to stackoverflow.com , it might be more suitable there. Also, try providing the information about what you have tried and which precise part gives you problems. – penelope Jan 14 at 9:43
Ok, thank you very much! – netom Jan 14 at 12:20

1 Answer

up vote 1 down vote accepted

The Hibert transform will produce a signal with 90 degree phase shift. Look in Numpy documentation at scripty.signal.hilbert as a start.

I'm not sure what you are actually trying to do, but you mentioned 90 degree phase shift and radio in the same post, so you may find the following article of use:

http://home.comcast.net/~szemengtan/LinearSystems/hilbert.pdf

share|improve this answer
Thank you Bruce, I missed this part. I'll check the docs. – netom Jan 14 at 16:00
Yepp, Mr. Hilbert solved my Problem. To put it into python: numpy.imag(scipy.signal.hilbert( <signal array> )) – netom Jan 15 at 6:35

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.