Signal Processing Toolbox

Filter Order

You have two mutually exclusive options for determining the filter order when you design an equiripple filter:

• Specify order: You enter the filter order in a text box.
• Minimum order: The filter design method determines the minimum order filter.

Select the Minimum order radio button for this example.

Note that filter order specification options depend on the filter design method you choose. Some filter methods may not have both options available.

Options

The available options depend on the selected filter design method. Only the FIR Equiripple and FIR Window design methods have settable options. For FIR Equiripple, the option is a Density Factor. See firpm for more information. For FIR Window the options are Scale Passband, Window selection, and for the following windows, a settable parameter

Window	Parameter
Chebyshev (chebwin)	Sidelobe attenuation
Gaussian (gausswin)	Alpha
Kaiser (kaiser)	Beta
Tukey (tukeywin)	Alpha
User Defined	Function Name, Parameter

You can view the window in the Window Visualization Tool (wvtool) by clicking the View button.

For this example, set the Density factor to 16.

Setting the Filter Design Specifications

Bandpass Filter Frequency Specifications

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