User`s guide

Key Reference 5
N9340B User’s Guide 103
Spectrum Emission Mask (SEM)
Spectrum Emission Mask measurement includes the
in- band and out- of- band spurious emissions. As it
applies to W- CDMA (3GPP), this is the power
contained in a specified frequency bandwidth at
certain offsets relative to the total carrier power. It
may also be expressed as a ratio of power spectral
densities between the carrier and the specified
offset frequency band. For WLAN, the reference
power is taken as the peak PSD in the signal, and
all offset results are also the peak PSD in that
offset as opposed to the integrated power.
Avg Number
Key access: [MEAS] > {More} > {SEM} > {Avg Number}
Press Avg Number (On) to specify the number of
measurement averages used when calculating the
measurement result. The average will be displayed
at the end of each sweep.
Meas Type
Key access: [MEAS] > {More} > {SEM} > {Meas Type}
Displays a menu where you can select a
measurement reference type, Tot al P wr R ef or PSD
Ref. When Tot al Pw r R ef is selected, the power in the
carrier is used as the reference in computing the
relative power values for the offsets. When PSD Ref
is selected, the mean power spectral density of the
carrier is used in computing the relative power
spectral density values for the offsets.
Ref Channel
accesses the softkeys that enable you to change the
reference channel settings:
• Chan Integ BW
Key access: [MEAS] > {SEM} > {Ref Channel}
Specifies the integration bandwidth used in
calculating the power in the main channel.