JDS Uniphase CellAdvisor JD780A Series, Руководство пользователя

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JD780A Series Analyzers
Using EV-DO Signal Analyzer
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Procedure
1.
Press the TRACE/DISPLAY hard key.
2.
Press the Select Trace soft key, and then select the trace number: T1 , T2 , T3 , T4 , T5 , or T6 .
The legend shape of the selected trace changes from square to round to indicate that the trace is
the active one now.
3.
Do one of the following:
To Select Trace Legend
Clear current data and display with new
measurements Clear Write W
Display the input signal
’s maximum response only
(unlimited or for a certain amount of time)
Max Hold M
Display the input signal
’s minimum response only
(unlimited or for a certain amount of time)
Min Hold m
Capture the selected trace and compare traces Capture C
Load a saved trace More (1/2) > Load L
Hide the selected trace Trace View > Off F
Remove all the traces and initialize the trace
settings More (1/2) > Trace
Clear All
NOTE
For the Max Hold and Min Hold , your instrument compares newly acquired data with the
active trace and displays larger maximum values or smaller minimum values on the
screen. You can set it to
Unlimited to hold and view maximum or minimum data or
specify a certain amount of time up to 60 seconds by using numeric keys or the rotary
knob.
4.
Optional . Press the More (1/2) > Trace Info soft key, and then select the trace number to view
the trace
’s parameter setting information stored at the time of the measurement or
None to hide
the information display.
5.
Optional. If you have the two traces T1 and T2, you can perform trace math. To view the power
difference between the traces, press the T1
– T2 -> T5
or T2
– T1 -> T6
soft key.
The result is overlaid on the screen along with the second Y-axis.
Conducting RF measurements
Channel power
The Channel Power measurement is a common test used in the wireless industry to measure the total
transmitted power of a radio within a defined frequency channel. It acquires a number of points
representing the input signal in the time domain, transforms this information into the frequency domain
using Fast Fourier Transform (FFT), and then calculates the channel power. The effective resolution
bandwidth of the frequency domain trace is proportional to the number of points acquired for the FFT.
The channel power measurement identifies the total RF power, power spectral density (PSD) and peak
to average ratio (PAR) of the signal in the EV-DO channel bandwidth (1.23 MHz).
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 181.