Rohde & Schwarz FPL1000 Series, User Manual

Page: 265 / 899

The Spectrum Application (RF Measurements)
R&S
®
FPL1000
265 User Manual 1178.3370.02 ─ 03
Reference Channel
The measured power values in the adjacent channels can be displayed relative to the
transmission channel. If more than one Tx channel is defined, define which one is used
as a reference channel.
Tx Channel 1 Transmission channel 1 is used.
Min Power Tx Channel The transmission channel with the lowest power is used as a reference channel.
Max Power Tx Chan-
nel The transmission channel with the highest power is used as a reference channel
(Default).
Lowest & Highest
Channel The outer left-hand transmission channel is the reference channel for the lower
adjacent channels, the outer right-hand transmission channel that for the upper
adjacent channels.
Remote command:
[SENSe:]POWer:ACHannel:REFerence:TXCHannel:MANual
on page 550
[SENSe:]POWer:ACHannel:REFerence:TXCHannel:AUTO
on page 550
Selected Trace
The CP/ACLR measurement can be performed on any active trace.
Remote command:
[SENSe:]POWer:TRACe
on page 541
Absolute and Relative Values (ACLR Mode)
The powers of the adjacent channels are output in dBm or dBm/Hz (absolute values),
or in dBc, relative to the specified reference Tx channel.
"Abs" The absolute power in the adjacent channels is displayed in the unit
of the y-axis, e.g. in dBm, dBµV.
"Rel" The level of the adjacent channels is displayed relative to the level of
the transmission channel in dBc.
Remote command:
[SENSe:]POWer:ACHannel:MODE
on page 556
Channel power level and density ( Power Unit )
By default, the channel power is displayed in absolute values. If "/Hz" is activated, the
channel power density is displayed instead. Thus, the absolute unit of the channel
power is switched from dBm to dBm/Hz.
Note: The channel power density in dBm/Hz corresponds to the power inside a band-
width of 1 Hz and is calculated as follows:
"channel power density = channel power – log
10
(channel bandwidth)"
Thus you can measure the signal/noise power density, for example, or use the addi-
tional functions
Absolute and Relative Values (ACLR Mode) and Reference Channel to
obtain the signal to noise ratio.
Remote command:
CALCulate<n>:MARKer<m>:FUNCtion:POWer:RESult:PHZ
on page 556
Measurements and Results