Varying the RF Signal in List or Sweep Mode
R&S
®
SMA100B
119
User Manual 1178.3834.02 ─ 03
Variable
Description
f
OFFSet
Frequency offset
f
STARt
Start frequency of the sweep range
f
STOP
End frequency of the sweep range
f
1
Current sweep frequency
f
2
Next, subsequent sweep frequency
step_lin
Step width in linear scaling
step_log
Step width in logarithmic scaling
POINts
Number of steps within the sweep range
Sweep range
The sweep range is defined by a start and an end value. How the remaining parame-
ters correlate is shown below.
Offset = 0
Sweep Range = f
STARt
to f
STOP
f
CENTer
= (f
STARt
+ f
STOP
)/2
f
SPAN
= (f
STOP
- f
STARt
)
Where:
f
STARt
= f
CENTer
- (f
SPAN
/2)
f
STOP
= f
CENTer
+ (f
SPAN
/2)
Offset
≠
0
A defined offset also affects the sweep range and the center frequency. Therefore, the
set frequencies are only absolute values, if the Offset = 0. Offset
≠
0 shifts the frequen-
cies with the offset value:
Sweep Range = f
STARt
+ f
OFFSet
to f
STOP
+ f
OFFSet
f
CENTer
= f
CENTer
+ f
OFFSet
f
SPAN
= f
SPAN
+ f
OFFSet
The value range of the instrument is calculated as follows:
RF
min
+ f
OFFSet
to RF
max
+ f
OFFSet
It is possible to set f
STARt
> f
STOP
and f
STARt
< f
STOP
, so that even a negative value is per-
mitted for the "Span".
If you change the start and/or stop frequency, the span and center frequency change
accordingly, and vice versa.
About Sweep Mode
