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fvtool

Visualize frequency response of digital down converter or digital up converter filter cascade

Syntax

fvtool(Conv)
fvtool(Conv,'Arithmetic',arithType)

Description

fvtool(Conv) plots the magnitude response of a digital down converter or digital up converter, Conv. By default, the object plots the cascade response up to the second CIC null frequency (or to the first when only one CIC null exists). To use this syntax, the object Conv must be locked.

example

fvtool(Conv,'Arithmetic',arithType) specifies the arithmetic type of the filters inside the converter. Set the 'Arithmetic' input to 'double', 'single', or 'fixed-point'. When the Conv object is in an unlocked state, you must specify the arithmetic type. When the Conv object is in a locked state, it ignores the arithmetic input argument.

For example, to plot the magnitude response of a digital down converter in an unlocked state, set the 'Arithmetic' input.

dwnConv = dsp.DigitalDownConverter
fvtool(dwnConv,'Arithmetic','fixed-point')

Examples

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Plot the magnitude response of the digital down converter using the fvtool function and the visualizeFilterStages function.

Create a dsp.DigitalDownConverter System object with the default settings. Using the fvtool function, plot the magnitude response of the overall filter cascade. The visualizeFilterStages function in addition plots the magnitude response of the individual filters stages.

dwnConv = dsp.DigitalDownConverter
dwnConv = 
  dsp.DigitalDownConverter with properties:

           DecimationFactor: 100
         MinimumOrderDesign: true
                  Bandwidth: 200000
    StopbandFrequencySource: 'Auto'
             PassbandRipple: 0.1000
        StopbandAttenuation: 60
                 Oscillator: 'Sine wave'
            CenterFrequency: 14000000
                 SampleRate: 30000000

  Show all properties

Using fvtool

If the System object is unlocked, you must specify the filter arithmetic through the 'Arithmetic' input of the fvtool function. If the System object is locked, the arithmetic input is ignored.

fvtool(dwnConv,'Arithmetic','fixed-point')

Using visualizeFilterStages

To view the magnitude response of the individual filter stages, call the visualizeFilterStages function.

visualizeFilterStages(dwnConv,'Arithmetic','fixed-point')

Input Arguments

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Digital down converter or digital up converter, specified as a dsp.DigitalDownConverter or dsp.DigitalUpConverter System object™.

When the Conv object is in an unlocked state, you must specify the arithmetic type. When the Conv object is in a locked state, it ignores the arithmetic input argument.

Introduced in R2012a