R&S ZVL
GUI Reference
Channel Menu
Operating Manual 1303.6580.32-06
263
An average over several sweeps reduces the influence of random effects in the measurement and
therefore minimizes the noise level. The effect increases with the average factor, however, obtaining an
averaged result requires several sweeps and therefore increases the measurement time.
The average factor is also valid for calibration sweeps: The calculation of system correction data is
based on the averaged trace.
Smoothing is an alternative method of compensating for random effects on the trace by averaging
adjacent measurement points. Compared to the sweep average, smoothing does not significantly increase
the measurement time but can eliminate narrow peaks and thus produce misleading results.
The sweep average is not frequency selective. To eliminate a spurious signal in the vicinity of the
measurement frequency, alternative techniques (e.g. a smaller filter bandwidth) must be used.
Calculation of sweep average
The average trace is obtained as follows:
Let c be the Average Factor and assume that n sweeps have been measured since the start of the
average cycle (start of the measurement or
Restart Average)
. The following two situations are
distinguished:
•
n < c: At each sweep point, the average trace no. n is calculated from the average trace no. n – 1
and the current trace no. n according to the following recurrence:
The average trace represents the arithmetic mean value over all n sweeps.
•
n > c: At each sweep point, the average trace no. n is calculated from the average trace no. n – 1
and the current trace no. n according to:
The formulas hold for Average Factor n = 1 where the average trace becomes equal to the current trace.
Remote control:
[SENSe<Ch>:]AVERage[:STATe] ON | OFF
[SENSe<Ch>:]AVERage:COUNt
[SENSe<Ch>:]AVERage:CLEar
Channel Select
The
Channel Select
submenu provides functions to create and delete channels and select a channel as
the active channel.
(No direct access via front panel keys)
