Chapter 2 195
One-Button Measurement Functions
Meas Setup (Spectrum Emissions Mask—SEM)
One-Button Measurement Functions
OFF|ON|0|1
[:SENSe]:SEMask:OFFSet[n]:LIST:BANDwidth|BWIDth[:RESolution]:AUTO?
Remote Command Notes: Comma separated list. When offset F is off, this will be 5
values. When offset F is on, this will be 6 values. n = 1 for BTS and n = 2
for MS. Default is BTS.
You may only enter valid Res BW filter frequencies.
See Volume 1, Core Spectrum Analyzer Functions User’s and
Programmer’s Reference guide.
Example: SEM:OFFS:LIST:BAND 40 kHz or SEM:OFFS:LIST:BWID 40 kHz
SEM:OFFS:LIST:BAND? or SEM:OFFS:LIST:BWID?
SEM:OFFS:LIST:BAND:AUTO 0 or SEM:OFFS:LIST:BWID:AUTO 0
SEM:OFFS:LIST:BAND:AUTO? or SEM:OFFS:LIST:BWID:AUTO?
2.19.4.6 Meas BW
Enables you to specify the bandwidth to use when measuring the offset. When using the
front panel, only the currently selected offset is affected. All the offsets are affected when
using the remote command. This is the multiplier applied to the resolution bandwidth to
determine the bandwidth to integrate when calculating the power.
Key Path: Meas Setup, Offset/Limits
Key Notes: The 3GPP standard allows for the construction of an effective
measurement bandwidth out of a group of narrower resolution
bandwidths. This allowance is a remedy for the potential loss in dynamic
range which can occur when carrier energy leaks into the offset due to the
RBW filter’s shape factor (nominally 12:1). When the offset’s ratio of start
frequency to the Meas BW is small (approximately 4:1), it is recommended
that you select a small Res BW value (30 kHz) and a large multiplier
(Meas BW=33) in order to increase the dynamic range of the
measurement. Refer to offset D in Table 2-2 on page188.
When setting Meas BW > 1, dynamic range is increased, however
measurement time is also increased since an increased number of sweep
points are required to make the measurement. For Meas BW > 1, consider
this equation for trace points:
Trace points = (Offset Stop Freq - Offset Start Freq)/ (Meas BW/100)
When Meas BW = 1, the number of trace points are set at the value
specified upon entering the measurement.
Dependencies/
Couplings: This parameter must adhere to the rule: (N x Res BW) ≤ (Stop Freq of the
offset - Start freq of the offset), where N is Meas BW value. If the Res BW
is changed, Meas BW will change to ensure this rule.