firtype
Determine type (1-4) of linear phase FIR filter System object
Syntax
Description
Examples
Hilbert Transformers
Design a Hilbert transformer of order 30 with a transition width of 0.2π rad/sample. Use least-squares minimization to obtain an equiripple linear-phase FIR filter. Plot the zero-phase response in the interval [–π,π).
d = fdesign.hilbert('N,TW',30,0.2); Hd = design(d,'equiripple',SystemObject=true); zerophase(Hd,'whole')
The impulse response of this even-order type-3 filter is antisymmetric.
impz(Hd)
ftype = firtype(Hd)
ftype = 3
Design a minimum-order Hilbert transformer that has a sample rate of 1 kHz. Specify the width of the transition region as 10 Hz and the passband ripple as 1 dB. Display the zero-phase response of the filter.
fs = 1e3; d = fdesign.hilbert('TW,Ap',10,1,fs); hd = design(d,'equiripple',SystemObject=true); zerophase(hd,-fs/2:0.1:fs/2,fs)
Input Arguments
sysobj
— Input FIR filter
FIR filter System object
Input FIR filter with real and linear phase, specified as one of the following filter System objects:
To check if a filter has linear phase, use the islinphase
function. To check if a filter has real coefficients, use the isreal
function.
Output Arguments
type
— FIR filter type
1
| 2
| 3
| 4
FIR filter type, defined as one of the following:
1
–– Type 1 filter with even order symmetric coefficients.
2
–– Type 2 filter with odd order symmetric coefficients.
3
–– Type 3 filter with even order antisymmetric
coefficients.
4
–– Type 4 filter with odd order antisymmetric
coefficients.
Version History
Introduced in R2013aR2024b: Support for dsp.VariableFIRDecimator
and dsp.VariableFIRInterpolator
Objects
Starting in R2024b, the firtype
analysis function supports the
dsp.VariableFIRDecimator
and dsp.VariableFIRInterpolator
objects.
R2023b: Support for dsp.ParallelFilter
and dsp.Delay
Objects
Starting in R2023b, the firtype
analysis function supports the
dsp.ParallelFilter
and the dsp.Delay
objects.
See Also
firtype
| islinphase
| isreal
MATLAB Command
You clicked a link that corresponds to this MATLAB command:
Run the command by entering it in the MATLAB Command Window. Web browsers do not support MATLAB commands.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)