Filter Design Toolbox™

fdesign.isinclp - Inverse-sinc filter specification

Syntax

d = fdesign.isinclp d = fdesign.isinclp(spec) d = fdesign.isinclp(spec,specvalue1,specvalue2,...) d = fdesign.isinclp(specvalue1,specvalue2,specvalue3,specvalue4) d = fdesign.isinclp(...,fs) d = fdesign.isinclp(...,magunits)

Description

d = fdesign.isinclp constructs an inverse-sinc lowpass filter specification object d, applying default values for the properties tw and ast.

Using fdesign.isinclp with a design method generates a dfilt object.

d = fdesign.isinclp(spec) constructs object d and sets its 'Specification' to spec. Entries in the spec string represent various filter response features, such as the filter order, that govern the filter design. Valid entries for spec are shown below. The strings are not case sensitive.

fp,fst,ap,ast (default spec)
n,fst,ap,ast
n,fp,fst

The string entries are defined as follows:

ast — attenuation in the first stop band in decibels (the default units). Also called Astop.
ap — amount of ripple allowed in the pass band in decibels (the default units). Also called Apass.
fp — frequency at the start of the pass band. Specified in normalized frequency units. Also called Fpass.
fst — frequency at the end of the first stop band. Specified in normalized frequency units. Also called Fstop.
n — filter order.

The filter design methods that apply to an inverse-sinc lowpass filter specification object change depending on the Specification string. Use designmethods to determine which design method applies to an object and its specification string.

d = fdesign.isinclp(spec,specvalue1,specvalue2,...) constructs an object d and sets its specifications at construction time.

d = fdesign.isinclp(specvalue1,specvalue2,specvalue3,specvalue4) constructs an object d assuming the default Specification property string fp,fst,ap,ast, using the values you provide in specvalue1,specvalue2, specvalue3, and specvalue4.

d = fdesign.isinclp(...,fs) adds the argument fs, specified in Hz to define the sampling frequency to use. In this case, all frequencies in the specifications are in Hz as well.

d = fdesign.isinclp(...,magunits) specifies the units for any magnitude specification you provide in the input arguments. magunits can be one of

linear — specify the magnitude in linear units
dB — specify the magnitude in dB (decibels)
squared — specify the magnitude in power units

When you omit the magunits argument, fdesign assumes that all magnitudes are in decibels. Note that fdesign stores all magnitude specifications in decibels (converting to decibels when necessary) regardless of how you specify the magnitudes.

Examples

Pass the specifications for the default specification — fp,fst,ap,ast — as input arguments to the specifications object.

d = fdesign.isinclp(.4,.5,.01,40);
designmethods(d)
hd = design(d,'equiripple');
fvtool(hd);

FVTool shows the classic inverse-sinc filter response.

fdesign.isinclp - Inverse-sinc filter specification

Syntax

Description

Examples

See Also