National Instruments NI 5102 用户手册
Chapter 3
Digitizer Basics
3-2
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Analog Bandwidth
Analog bandwidth describes the frequency range (in hertz) in which a
signal can be digitized accurately. This limitation is determined by the
inherent frequency response of the input path—from the tip of the probe
to the input of the ADC—which causes loss of amplitude and phase
information. Analog bandwidth is the frequency at which the measured
amplitude is 3 dB below the actual amplitude of the signal. Figure 3-2
illustrates the effect of analog bandwidth on a high-frequency signal.
The result is a loss of high-frequency components and amplitude in the
original signal as the signal passes through the digitizer.
signal can be digitized accurately. This limitation is determined by the
inherent frequency response of the input path—from the tip of the probe
to the input of the ADC—which causes loss of amplitude and phase
information. Analog bandwidth is the frequency at which the measured
amplitude is 3 dB below the actual amplitude of the signal. Figure 3-2
illustrates the effect of analog bandwidth on a high-frequency signal.
The result is a loss of high-frequency components and amplitude in the
original signal as the signal passes through the digitizer.
Figure 3-2. Analog Bandwidth
Bandwidth
+2 V
+1 V
0 V
0 V
+1/2 V
–1/2 V
–1 V
–2 V
Input Signal
Instrument
Measured Signal
a
b
c
a
b
c