Continuous zoom fft, Frequency response measurement, Continuous zoom fft frequency response measurement – National Instruments NI Spectral Measurements Toolkit User Manual

Page 9

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9

NI Spectral Measurements Toolkit User Guide

The channel specification parameter specifies the center frequency,
bandwidth, and spacing for the ACP measurement. The bandwidth
parameter
specifies the width of each channel. The spacing parameter
specifies the separation between the center frequencies of each channel.
The Units [rms] parameter specifies the units for the ACP measurement.
The Power Spectrum parameter is a waveform graph that shows the power
spectrum with the three channels, or bands, and the power in each channel.
The Advanced Settings tab of the example includes some of the same
controls as the SMT Spectrum Analyzer (simulated) example, such as
Averaging Parameters.

Using LabWindows/CVI Spectral Measurements
Examples

This section describes some of the LabWindows/CVI programming
examples located in the

<

LabWindows/CVI>\samples\smt

folder. You

can use these example programs as a starting point for your applications.
The

simulated

folder contains examples that use a simulated source. Use

these examples to explore different features of the Spectral Measurements
Toolkit without using a data acquisition device.

Continuous Zoom FFT

The Continuous Zoom FFT example is located at

samples\smt\

simulated\smtcz\smtcz.prj

.

This example demonstrates how to configure the zoom FFT, then calculates
an averaged power spectrum using the continuous zoom FFT technique.
It demonstrates how to display the spectrum in different RF units.

Frequency Response Measurement

The Frequency Response Measurement example is located at

samples\

smt\simulated\smtfqres\smtfqres.prj

.

This example demonstrates how to configure the zoom FFT, then calculates
the averaged frequency response of a stimulus and response signal from
a device under test. The example uses the block zoom FFT technique.
The example uses handles to maintain state information between functions,
such as

SmtConfigZoomFFT

and

SmtZoomFFT

.

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