JDS Uniphase CellAdvisor JD780A Series, Руководство пользователя

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JD780A Series Analyzers
Using EV-DO Signal Analyzer
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NOTE
You can use the LIMIT hot key to analyze your measurements with the user-definable
limit and Pass/Fail indication. See
“Setting limit for RF tests” on page 385 for more
information.
Spectrum emission mask (SEM)
The Spectrum Emission Mask (SEM) measurement required by 3GPP2 specifications encompasses
different power limits and different measurement bandwidths (resolution bandwidths) at various
frequency offsets. It may be expressed as a ratio of power spectral densities between the carrier and
the specified offset frequency band. It provides useful figures-of-merit for the spectral re-growth and
emissions produced by components and circuit blocks, without the rigor of performing a full SEM
measurement.
The SEM measures spurious signal levels in up to five pairs of offset or region frequencies and relates
them to the carrier power.
Setting measure setup
After configuring test parameters as described in the
“Configuring test parameters” on page 373, your
measurement result is displayed on the screen as like the following example, Figure 183.
Figure 183 SEM measurement with EV-DO signal analyzer
NOTE
You can use the LIMIT hot key to analyze your measurements with the user-definable
limit and Pass/Fail indication. See
“Setting limit for RF tests” on page 385 for more
information.
ACPR
The Adjacent Channel Power Ratio (ACPR) is defined as the ratio of the average power in the
adjacent frequency channel (or offset) to the average power in the transmitted frequency channel. It
may be expressed as the ratio of the integrated signal power in the adjacent channel to the integrated
signal power in the main channel.