Anrtisu Site Master S331D - Adjacent Channel Power Ratio

Adjacent Channel Power Ratio
Another common transmitter measurement is that of adjacent channel leakage power. This
is defined as the ratio of the amount of leakage power in an adjacent channel to the total
transmitted power in the main channel. This measurement can be used to replace the tradi
-
tional two-tone intermodulation distortion (IMD) test for system non-linear behavior.
The result of an ACPR measurement can be expressed either as a power ratio or a power
density. In order to calculate the upper and lower adjacent channel values, the Site Master
requires the specification of four parameters:
q
Main Channel Frequency
q
Measurement Channel Bandwidth
q
Adjacent Channel Bandwidth
q
Channel Spacing
Required Equipment
q
Site Master S332D
q
Portable antenna for the selected signal frequency
Procedure
Step 1.
On the Site Master, press the MODE key, use the Up/Down arrow key to select
the
Spectrum Analyzer mode and press ENTER.
Step 2. Press the Signal Standard soft key, select the appropriate network standard, and
press ENTER.
Step 3.
Press the
Select Channel soft key, enter a value and press ENTER.
NOTE: For ACPR measurements, when the appropriate Channel is selected,
the Main channel bandwidth, Adjacent channel bandwidth and channel spacing
are automatically set.
Step 4.
Press the AMPLITUDE key and select the
Ref Level soft key to set the reference
level to an appropriate value.
Step 5. Press the
Atten/Preamp soft key and set the attenuation to Auto.
Step 6.
Press the MEAS/DISP key and select the
Bandwidth soft key to set the resolu
-
tion bandwidth and the video bandwidth to Auto.
Step 7. Press the
Back soft key to return to the previous menu.
Step 8. Press the
Trace soft key and the Max Hold soft key to set max hold to On as indi
-
cated to the left of the graph.
Step 9. Press the Measure soft key and press the ACPR soft key.
Step 10. Make the measurement by pressing the
Measure soft key. The detection method
is automatically changed to RMS Average. Solid vertical lines are drawn on the
display to indicate the main channel. Dashed vertical lines define the adjacent
channels. The Site Master will display the measurement results.
5-14
Chapter 5 Spectrum Analyzer Measurements