Rohde & Schwarz CMU-K20, Operating Manual

Page: 37 / 646

CMU-K20/-K21/-K22/-K23/-K24 Preparing a GSM Mobile Phone Test
1115.6088.12 2.3 E-10
Additional Information... Alternative Settings
and Measurements
... on Step 1
"
Mains switch on the rear panel
When the mains switch at the rear is set to the OFF position,
the complete instrument is disconnected from the power sup-
ply. When it is set to the ON position, the instrument is in
standby mode or in operation, depending on the position of
the
ON/STANDBY key on the front panel.
'
chapter 1 of CMU manual
#
ON/STANDBY key on the front panel
The ON/STANDBY key at the front of the instrument deter-
mines whether the instrument is in standby mode or in opera-
tion.
Standby mode:
Only the reference frequency oscillator is supplied with oper-
ating voltage, and the orange LED (STANDBY) is illuminated.
O peration:
The green LED (ON) is illuminated and all modules of the in-
strument are supplied with operating voltage.
... on Step 2
$
RF connection of the mobile phone
A high-quality cable should be used for this connection, ide-
ally with an attenuation of less than 0.5 dB. For portable
phones, the car installation set supplied by telephone manu-
facturers can be used.
%
Power supply for the mobile phone
In case the mobile phone is operated from an external power
supply, make sure that it is capable of supplying the maxi-
mum peak current required. As GSM mobile phones gener-
ate pulse-like RF signals, they often feature a pulse-shaped
current consumption. Problems may arise if power supplies
are used which cannot provide such currents with a constant
voltage.
... on Step 3
The CMU provides two bi-
directional RF connectors RF1
and RF2 differing by their permis-
sible input and output levels. RF1
is the recommended standard
connector for GSM mobile
phones, RF2 for handheld
phones (see data sheet).
The unidirectional connectors
RF4 IN and RF3 OUT are in-
tended for connection of modules
requiring high input levels or
modules with low RF output lev-
els. RF4 IN and RF3 OUT can
also be used to connect GSM
mobiles off the air via antennas.
Input and output connectors can
be selected in the
RF tab of
the Connect. Control menu.
&
Startup menu
The startup menu displays the following information:
•
The startup procedure ( Process)
•
Instrument model, serial number and version of the CMU
base software
(Info)
•
Installed hardware and software options and equipment
(Options) . Available software options are listed with their
version numbers.
•
Progress of the startup procedure ( Startup bar graph).
'
chapter 4 of CMU manual
That chapter also contains infor-
mation on customizing the CMU.
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