R&S FSW Series, Руководство пользователя

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Measurements and Results
R&S
®
FSW
175 User Manual 1173.9411.02 ─ 43
The Tx channel bandwidth is normally defined by the transmission standard.
The correct bandwidth is set automatically for the selected standard. The bandwidth for
each channel is indicated by a colored bar in the display.
For measurements that require channel bandwidths which deviate from those defined
in the selected standard, use the IBW method ("Fast ACLR" "Off"). With the IBW
method, the channel bandwidth borders are right and left of the channel center fre-
quency. Thus, you can visually check whether the entire power of the signal under test
is within the selected channel bandwidth.
The value entered for any Tx channel is automatically also defined for all subsequent
Tx channels. Thus, only enter one value if all Tx channels have the same bandwidth.
The value entered for any ADJ or ALT channel is automatically also defined for all
alternate (ALT) channels. Thus, only enter one value if all adjacent channels have the
same bandwidth.
Remote command:
[SENSe:]POWer:ACHannel:BANDwidth[:CHANnel<ch>]
on page 845
[SENSe:]POWer:ACHannel:BANDwidth:ACHannel
on page 844
[SENSe:]POWer:ACHannel:BANDwidth:ALTernate<ch>
on page 844
Channel Spacings
Channel spacings are normally defined by the transmission standard but can be
changed.
If the spacings are not equal, the channel distribution in relation to the center frequency
is as follows:
Odd number of Tx channels The middle Tx channel is centered to center frequency.
Even number of Tx channels The two Tx channels in the middle are used to calculate the fre-
quency between those two channels. This frequency is aligned to
the center frequency.
The spacings between all Tx channels can be defined individually. When you change
the spacing for one channel, the value is automatically also defined for all subsequent
Tx channels. This allows you to set up a system with equal Tx channel spacing quickly.
For different spacings, set up the channels from top to bottom.
Tx1-2 Spacing between the first and the second carrier
Tx2-3 Spacing between the second and the third carrier
… …
If you change the adjacent-channel spacing (ADJ), all higher adjacent channel spac-
ings (ALT1, ALT2, …) are multiplied by the same factor (new spacing value/old spacing
value). Again, only enter one value for equal channel spacing. For different spacing,
configure the spacings from top to bottom.
For details, see Chapter 7.2.6.2, "How to Set Up the Channels" , on page 195
Channel Power and Adjacent-Channel Power (ACLR) Measurement