today I have a little question: Is it possible to turn a common
FIR-bandpass into a bandpass with 90 degree phase shift? And if
possible, how to do?
My usual procedure:
1. make a lowpass for the lower frequency edge (sin(x)/x * Blackmann)
2. make a second lowpass for the upper frequency edge (also sin(x)/x *
3. normalize both lowpasses
4. turn the second lowpass per spektral inversion to a highpass
5. add both passes, this makes a band reject pass
6. turn it into a band pass by spektral inversion
This makes all the taps for a decent FIR-bandpass, it works fine for
even as well as for odd tap numbers, but without any phase shift.
The output is limited to the desired frequency span as requested, so I
hope it should be possible to add a 90 degree phase shift to it (a la
A decent testbench for the a.m. filter I already have written for
myself, but not yet for a added Hilbert transformation.
so, has anyone a nice idea for this?