Tektronix TDS5054, Руководство пользователя

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Creating and Using Math Waveforms
TDS5000 Series User Manual
3- 151
Defining Spectral Math Waveforms
The math capabilities of the oscilloscope include waveform spectral analysis.
This section describes how you can control the analysis intuitively with time
domain and frequency domain controls. These controls merge the time domain
controls with the frequency domain controls to provide a complete spectral
analyzer.
NOTE
. This type of advanced spectral analysis is only available if you purchase
Option 2A, Advanced Analysis. The math capabilities that come standard with
this oscilloscope allow you to define a scale and window type to create an FFT
magnitude spectrum.
Signals may be represented by their characteristics in both the time and the
frequency domain. By combining and transforming source waveforms into
spectral math waveforms, you can simultaneously view signal characteristics in
both domains.
This spectral analyzer provides a complete set of controls and features that allow
you to make time and frequency domain measurements without the need to learn
extensive details about FFT algorithms.
H
Frequency Domain Controls: Use traditional spectrum analyzer controls to
set the center frequency, span, and resolution bandwidth directly.
H
Time Domain Controls:
The time domain controls for the acquired waveform
set the time duration and the resolution time between samples. You can
easily set the required sample rate and record length.
H
Gating Controls: These controls are the bridge that connects the time domain
to the frequency domain. You can perform spectral analysis on a gated region
of the input waveform. This gating also determines the resolution bandwidth.
H
Window Functions: Eight different window functions are available to shape
the filter response.
H
Magnitude Versus Frequency: Display log data in dB, dBm, or linear mode.
You can display the real or imaginary parts of the spectral magnitude only.
Reference level offset and reference level controls give complete control over
the vertical position and offset of the spectrum.
H
Phase Versus Frequency: Display phase data as a function of frequency in
radians or degrees. You may zero the noise phase for magnitudes below a
threshold level. Finally, you may select Phase unwrap and d
θ
/d
ω,
group
delay.
H
Spectral Averaging: You can turn on averaging in the frequency domain for
phase and magnitude waveforms.