Operating instructions

R&S ESCI More Complex Programming Examples
1166.6004.12 7.19 E-1
Operation with Fixed Reference Point (Reference Fixed)
The following example is based on a signal with a level of –20 dBm at 100 MHz. The harmonics of the
signal lie at 200 MHz, 300 MHz, etc. In the presence of high-quality signal sources these harmonics may
be outside the dynamic range of the R&S ESCI. In order to measure harmonic suppression, however,
the level must be set to higher sensitivity for measuring the harmonics; the carrier has to be suppressed
by a notch filter to avoid overloading the R&S ESCI RF input.
In the following example, two measurements are therefore performed with different level settings, first
with a high reference level at the carrier frequency and then with a low reference level at the frequency
of the 3
rd
harmonic.
The default setting of the R&S ESCI for measurements (SetupInstrument) is used as starting point and
adaptations are then made for the measurement.
REM ************************************************************************
Public Sub RefFixed()
result$ = Space$(100)
CALL SetupInstrument 'Default setting
'--------------- Measure the reference point -------------------------------
CALL IBWRT(receiver%,"INIT:CONT OFF") 'Single sweep
CALL IBWRT(receiver%,"CALC:MARK:PEXC 6DB") 'Peak Excursion
CALL IBWRT(receiver%,"CALC:MARK:STAT ON") 'Marker1 on
CALL IBWRT(receiver%,"CALC:MARK:TRAC 1") 'Assign Marker 1 to Trace 1
CALL IBWRT(receiver%,"INIT;*WAI") 'Perform sweep with sync
CALL IBWRT(receiver%,"CALC:MARK:MAX") 'Set Marker1 to 100 MHz
CALL IBWRT(receiver%,"CALC:DELT:FUNC:FIX ON") 'Reference fixed
'-----Setting frequency, level and bandwidth for harmonic measurement ----
CALL IBWRT(receiver%,"FREQ:CENT 400MHz;Span 1MHz" )'Set freq. of 3
rd
harmonic
CALL IBWRT(receiver%,"BAND:RES 1kHz") 'and appropriate RBW
CALL IBWRT(receiver%,"SWEEP:TIME:AUTO ON") 'Couple sweep time
CALL IBWRT(receiver%,"INP:ATT:AUTO ON") 'Optimize level
CALL IBWRT(receiver%,"DISP:WIND:TRAC:Y:RLEV –50dBm")
CALL IBWRT(receiver%,"INIT;*WAI") 'Perform sweep with sync
CALL IBWRT(receiver%,"CALC:DELT:MODE REL") 'Delta marker frequency
'relative
CALL IBWRT(receiver%,"CALC:DELT:MAX;X?;Y?") 'Read out delta marker
Call ibrd(receiver%, result$) 'Read out frequency and level
Print "Deltamarker 1: "; result$
END SUB
REM
************************************************************************