Oscilloscope Bandwidth And Sample Rate - Agilent Technologies InfiniiVision 2000 X-Series User Manual

11
Acquisition Control

Oscilloscope Bandwidth and Sample Rate

An oscilloscope's bandwidth is typically described as the lowest frequency
at which input signal sine waves are attenuated by 3 dB (- 30% amplitude
error).
At the oscilloscope bandwidth, sampling theory says the required sample
rate is f
components above f
an ideal brick- wall frequency response.
Figure 22
However, digital signals have frequency components above the fundamental
frequency (square waves are made up of sine waves at the fundamental
frequency and an infinite number of odd harmonics), and typically, for
500 MHz bandwidths and below, oscilloscopes have a Gaussian frequency
response.
146
= 2f . However, the theory assumes there are no frequency
S BW
(f
MAX BW
Theoretical Brick-Wall Frequency Response
Agilent InfiniiVision 2000 X-Series Oscilloscopes User's Guide
in this case) and it requires a system with