R&S FSL Measuring the Magnitude and Phase of a Signal
1300.2519.12 7.21 E-11
CALL InstrWrite(analyzer,"CORR:TRAN:SCAL LIN")
'Linear frequency–axis
CALL InstrWrite(analyzer,"CORR:TRAN:COMM 'Simulated cable correction'")
cmd$ = "CORR:TRAN:DATA " 'Enter frequency and level
cmd$ = cmd$ + "10MHz, 0," 'values. Level values without
cmd$ = cmd$ + "100MHz, 3," 'unit!
cmd$ = cmd$ + "1GHz, 7,"
cmd$ = cmd$ + "3GHz, 10"
CALL InstrWrite(analyzer,cmd$) 'Enter frequency and level values
'––––––––– Activate transducer –––––––––––––––––––––––––––––––––––––––
CALL InstrWrite(analyzer,"CORR:TRAN:STAT ON")
'Activate transducer factor
END SUB
REM ************************************************************************
Measuring the Magnitude and Phase of a Signal
Due to the R&S FSL's internal architecture, it is capable of measuring and outputting the magnitude and
phase of a signal in addition to its power values. This opens up a variety of possibilities for more in–
depth analysis (FFT, demodulation, etc).
I/Q data is stored in memory areas each containing 512 k words. Hardware triggering controls the
memory.
The following example shows the steps necessary to collect data at a predefined sampling rate and
read it from the I/Q memory.
Data is output in the form of voltage values referred to the analyzer input. Data can be read in binary or
ASCII format.
In binary format, the length information carried in the message header is evaluated and used for
calculating the x–axis values.
In ASCII format, only a list of voltage values is output.
Binary data is read in three steps:
1. The number of digits carrying the length information is read.
2. The length information itself is read.
3. The trace data is read.
This procedure is necessary with programming languages like Visual Basic which support only
structures of identical data types (arrays), whereas the binary data format uses different data types in
the header and the data section.
Note: The arrays for measured data are dimensioned in such a way that they can accommodate the
I/Q data of the R&S FSL (2 x 512 k).
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