Snr And Noise Level; Figure 5-9 Sinad Measurement - Agilent Technologies U8903A User Manual

Audio Analyzer Measurement Functions 5
The SINAD measurement is shown as follows.

Figure 5-9 SINAD measurement

SNR and Noise Level

Signal- to- noise ratio (SNR) is defined as the ratio of the
signal amplitude to noise amplitude. Both the signal and
noise amplitude must be measured at the same or equivalent
points in a system, and within the same system bandwidth.
The U8903A implementation of the SNR measurement is a
closed loop configuration in which both the generator and
the analyzer are used in the test setup. Channel 1 of the
generator will be used for measurement on the analyzer
channel 1.
The SNR for an audio system such as an amplifier at a
specified input or output level is the ratio between the
output signal power and noise level. An SNR value is further
defined by the measurement bandwidth specification. The
measurement bandwidth is up to 20 kHz, with or without
weighting filters. Refer to Chapter 3, "Input Settings" on
page 56 for the information on selecting the input settings.
U8903A User's Guide 97