Offset Calibration - Anritsu spectrum master ms2711d User Manual

Chapter 6 Power Measurement

Offset Calibration

One of the main contributors to measurement error when measuring the power coming out
of a base station is to assume that the combined loss of the phase stable cable and the at-
tenuator connected to the output of the instrument is exactly the same as the specified value
of the attenuator. An offset calibration can be used to measure the loss of the attenuator and
cable using a scalar measurement.
The instrument measures the loss of the phase stable cable and the attenuator and uses this
value to subtract the loss for the selected frequency range. The original characterization is
done over the entire frequency range, so there is no need to perform additional calibrations
when the frequency range is changed. The calibration automatically disappears when the in-
strument is rebooted. It is possible to recall the last calibration and it is also possible to ap-
ply this offset cal feature to other modes as well (GSM, CDMA, EVDO, SPA).
Required Equipment
MS2711D Spectrum Master
·
Test Port Extension Cable, Anritsu 15NNF50 – 1.5C
·
18" (46cm) Test Port Extension Cable, Anritsu 3-806-151
·
10 dB Attenuator, Anritsu 3-1010-119
·
30 dB, 50W, bi-directional, DC–18 GHz, N(m) – N(f), Attenuator, Anritsu 42N50A-30
·
Procedure
Step 1. Press the ON/OFF key on the Spectrum Master.
Step 2. Press the MODE key.
Step 3. Use the Up/Down arrow key to select the Power Meter mode and press
ENTER.
Step 4. Press the START CAL (3) key.
Step 5. Connect the 10 dB Attenuator to the RF Out connector.
Step 6. Connect the 18" (46cm) Test Port Extension Cable to the RF In connector and
the 10 dB Attenuator.
Figure . Setup for Normalizing the Trace
6-4
18" Cable
3-806-151
10 dB Attenuator
RF In 3-1010-119
MS2711D
Spectrum Master
1
TRACE
3
SAVE
SETUP
5
LIMIT
7
SAVE
DISPLAY
9
ON
OFF
MODE FREQ / SPAN AMPLITUDE BW/SWEEP
RF Out
ESCAPE
2 CLEAR
MEAS
4
RECALL
SETUP
6
MARKER
ENTER
8
RECALL SINGLE
DISPLAY CONT
0 + /
-
PRINT
SYS
.