Tx Level Error; Vswr; Tx Level Settling Time; Tx Harmonics - Rohde & Schwarz CRTU-RU Service Manual

Manual Test Procedure
Control:
Test: Time from trigger point when the specified offset (< 1 kHz) from the stop
frequency is reached.

TX Level Error

Preparation: Test setup TX1 to TX4 (depending on level range).
Control:
Test:
Note: The given frequencies and levels are suggested values. Of course, it is also possible to use
other values for the measurement.

VSWR

Preparation:
Control:
CRTU Radio Unit: Switch generator on and set level to minimum (–130 dBm or
Test:

TX Level Settling Time

Test setup TX5.
Preparation:
CRTU Radio Unit: Connector RF3 OUT 1GHz, Ramping On, Hopping Off.
Analyzer:
Control:
Test:

TX Harmonics

Preparation: Test setup TX5, no external trigger
Analyzer:
Control:
1140.0050.82
Set CRTU Radio Unit to desired frequencies and hopping, level 0 dBm.
Set CRTU Radio Unit to desired connector, frequency and level (RF Analyzer
must be OFF).
Measure the TX level of the CRTU Radio Unit.
Connect (scalar) network analyzer to RF1, RF2, RF3 OUT, RF4 IN one after
the other.
Cable losses must be corrected.
–90 dBm), switch RF wideband analyzer on (RF1/RF2/RF4 IN).
Measure VSWR at 10 MHz, 900 MHz, 1800 MHz, 2700 MHz.
Sweep time = 40 µs, Center = 1 GHz , Span = 0, RBW = 10
MHz, external trigger.
Set CRTU Radio Unit to frequency = 1 GHz, specified level and ramping
mode.
The time period from the trigger point to the point in time when the nominal
level < 0.5 dB has been reached is measured.
Center = 2 x f
Set CRTU Radio Unit to connector RF1, specified frequency, level = –27 dBm.
Radio Unit R&S
or Center = 3 x f
nom
1.14
CRTU-RU
, Span = 1 MHz.
nom
E-4