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S:\Hp8960\E1962B CDMA 2000\Pi Release\Reference Guide\Chapters\cdma2000_meas_saudio_desc.fm
Swept Audio Measurements Description
Swept Audio Measurements Description
Description
How are swept audio measurements made?
Swept audio measurements synchronize the frequencies of the test set’s audio generator and audio analyzer
instruments to automatically make measurements at up to 60 frequency points. Audio level, SINAD, and
distortion measurements can be performed at each measurement point in the sweep.
This measurement only generates and analyzes audio signals; no modulation of the RF generator, or
demodulation by the receiver, is performed. A representation of this operation is shown below.
Figure 5. Swept Audio Measurements Block Diagram
The audio generator’s signal is output through the front panel AUDIO OUT port to the device under test. The
audio signal from the device under test is sent to the audio analyzer through the AUDIO IN ports.
The start and stop frequencies for the sweep define the frequency range. The user specifies the number of
measurement points, which are evenly spaced through the specified frequency range.
Measurement settling time can be set to specify how long the audio signal is generated at each frequency
before a measurement is made by the audio analyzer. This is used to account for settling time in the device
being tested and any signal delay through the device. Increasing the settling time increases the sweep time.
If the 100 Hz BW bandpass filter is selected, the center frequency of the filter is synchronized to the audio
generator and audio analyzer frequencies.
Typical applications include measuring the audio distortion of a mobile station across several frequencies and
measuring the frequency response of an audio filter or amplifier.
This is not a measurement procedure specified in the EIA/TIA standards.
Audio Generator
(DC)(AC)
Level
Coupling
Start Frequency
Stop Frequency
Number of Points
AUDIO
OUT
Filter Type
Audio
In
High Low
SINAD Measurement
Distortion Measurement
RMS
Peak
Detector Type
Audio Level
Measurement
Expected Peak Voltage
Audio Analyzer Instrument
Shared Controls
Device Under
Test
Device Settling Time
Instrument
(These controls affect
both instruments when
making swept audio
measurements.)
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