Filter Design Toolbox

firlp2hp

Convert FIR Type I lowpass filter to Type I FIR highpass filter

Syntax

• g = firlp2hp(b)
  g = firlp2hp(b,'wide')
  

Description

g = firlp2hp(b) transforms the type I lowpass FIR filter b with zero-phase response Hr(w) into a type I highpass FIR filter g with zero-phase response Hr(-w).

The passband and stopband ripples of g will be equal to the passband and stopband ripples of b.

g = firlp2hp(b,'wide') transforms the Type I lowpass FIR filter b with zero-phase response Hr(w) into a Type I highpass FIR filter g with zero-phase response 1 - Hr(w).

For this case, the passband and stopband ripples of g will be equal to the stopband and passband ripples of b.

Examples

Overlay the original narrowband lowpass and the resulting narrowband highpass and wideband highpass

• b = gremez(36,[0 .2 .25 1],[1 1 0 0],[1 3]);
  zerophase(b); hold on;
  h = firlp2hp(b);
  zerophase(h);
  g = firlp2hp(b,'wide');
  zerophase(g); hold off
  

See Also

firlp2lp

zerophase in your Signal Processing Toolbox documentation

References

[1]  Saramaki, T, Finite Impulse Response Filter Design, Handbook for Digital Signal Processing. S.K. Mitra and J.F. Kaiser Eds. Wiley-Interscience, N.Y., 1993, Chapter 4.

firlp2lp

firlpnorm