Signal Processing Toolbox

Response Type Region

Choose a response type from the mutually exclusive radio buttons.

• Lowpass
• Raised Cosine (firrcos)
• Highpass
• Bandpass
• Bandstop
• Other Response Types (in pull-down menu)
• Differentiator (firpm, firls)
• Multiband (firpm, firls)
• Hilbert Transformer (firpm, firls)
• Arbitrary Magnitude (firpm, firls)

Note    Other filter response types are available with the Filter Design Toolbox.

The response type you choose is reflected in the Display, Options, Frequency Specifications, and Magnitude Specifications regions.

Lowpass Filters

When you select this option, a lowpass filter is displayed in the Display region, and the Frequency Specifications and Magnitude Specifications regions are updated with the appropriate parameters.

See butter, cheby1, cheby2, ellip, firpm, fircls, firls, or fir1 for more information.

Raised Cosine Filters

When you select this option, a raised cosine filter is displayed in the Display region, and the Frequency Specifications and Magnitude Specifications regions are updated with the appropriate parameters.

Raised Cosine (RC) filters are linear-phase, lowpass filters with raised cosine transition bands. At low frequencies the passband is flat. The transition band rolls off in a cosine shape towards the stopband. Digital communications systems often use RC filters to reduce intersymbol interference. See firrcos for more information.

Highpass Filters

When you select this option, a highpass filter is displayed in the Display region, and the Frequency Specifications and Magnitude Specifications regions are updated with the appropriate parameters.

See butter, cheby1, cheby2, ellip, firpm, fircls, firls, or fir1 for more information.

Bandpass Filters

When you select this option, a bandpass filter is displayed in the Display region, and the Frequency Specifications and Magnitude Specifications regions are updated with the appropriate parameters.

See butter, cheby1, cheby2, ellip, firpm, fircls, firls, or fir1 for more information.

Bandstop Filters

You can specify the frequencies that determine the pass band and the stopband. When you select this option, a bandstop filter is displayed in the Display region, and the Frequency Specifications and Magnitude Specifications regions are updated with the appropriate parameters.

See butter, cheby1, cheby2, ellip, firpm, fircls, firls, or fir1 for more information.

Other Response Types

Differentiator Filters.   A differentiator filter generates the derivative of the input signal. See Multiband FIR Filter Design with Transition Bands and firpm for more information.

Multiband Filters.   A multiband filter has multiple passbands interleaved with multiple stopbands. See Multiband FIR Filter Design with Transition Bands and firpm for more information.

Hilbert Transformer Filters.   A Hilbert transformer is a filter that generates an approximation of the discrete Hilbert transform of the input signal. See Multiband FIR Filter Design with Transition Bands and firpm for more information.

Arbitrary Magnitude Filters.   An arbitrary magnitude filter can be designed to have any desired magnitude response shape. See Multiband FIR Filter Design with Transition Bands and firpm for more information.

Design Filter Panel

Design Method Region

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