Chapter 3
GSM Asynchronous Mode Operation
Spectrum measurements
4460 GSM System Option and 4468 EDGE System Option
Version 12.20
145
On first sight
The mobile’s modulation spectrum is displayed graphically in the menu’s live
display. The live display is updated continuously. To read the exact measurement
at any position, simply use the display markers.
The current main parameters and the status are displayed in the lower right
corner of the menu.
The softkeys provide access to important tools of the spectrum analyzer.
The Spectrum Live Display
The live display is updated continuously (as long as it has not been frozen).
The vertical axis of the spectrum live display is in dBm; the horizontal axis in
MHz.
The selection field
Max Level
allows to set the maximum power level to opti-
mize the vertical resolution.
Display field
dBm
shows the maximum RF power level measured on the center
frequency.
Selection fields
Res BW
and
Span
allow to set the resolution and frequency
span for the horizontal axis of the live display.
Max Level —
This selection field allows to set the RF power level that is repre-
sented by the top horizontal line of the live display.
Selections possible are: from +40 dBm to –40 dBm in steps of 10 dB.
NOTE
The maximum RF power level measured at the center frequency is displayed
on the
dBm
display field just right to this entry field.
NOTE
The value selected here should be equal or slightly higher than the expected
maximum RF power level on the measurement frequency in order to avoid
overload distortion and to achieve maximum vertical resolution.