Hilbert Filter Coefficient Calculation¶
- Author or source: ed.luosfosruoivas@naitsirhC
- Type: Uncle Hilbert
- Created: 2005-04-17 19:05:37
This is the delphi code to create the filter coefficients, which are needed to phaseshift
a signal by 90°
This may be useful for an evelope detector...
By windowing the filter coefficients you can trade phase response flatness with magnitude
response flatness.
I had problems checking its response by using a dirac impulse. White noise works fine.
Also this introduces a latency of N/2!
1 2 3 4 5 6 7 8 9 10 11 12 | type TSingleArray = Array of Single;
procedure UncleHilbert(var FilterCoefficients: TSingleArray; N : Integer);
var i,j : Integer;
begin
SetLength(FilterCoefficients,N);
for i:=0 to (N div 4) do
begin
FilterCoefficients[(N div 2)+(2*i-1)]:=+2/(PI*(2*i-1));
FilterCoefficients[(N div 2)-(2*i-1)]:=-2/(PI*(2*i-1));
end;
end;
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