R&S SMJ100A, Руководство по эксплуатации

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Instrument Function
R&S
®
SMJ100A
285 Operating Manual 1403.7458.32 ─ 14
If activated, the settings for leakage, I/Q imbalance and quadrature offset become
effective.
Whether or not I/Q impairment is activated is indicated in the function block.
Note: It is advisable to switch automatic level control to the Sample&Hold mode, as
otherwise level errors may occur (see Chapter 5.5.7, "Automatic Level Control - ALC" ,
on page 220).
Remote command:
[:SOURce<hw>]:IQ:IMPairment[:STATe]
on page 726
Offset - I/Q Mod
Sets the carrier offset (in percent) of the amplitudes (scaled to the peak envelope
power (PEP) for the I and/or Q signal component. An ideal I/Q modulator suppresses
the carrier offset completely (offset = 0 percent).
For more information, see Chapter 5.7.1.2, "I and Q Offset" , on page 290.
Remote command:
[:SOURce<hw>]:IQ:IMPairment:LEAKage:I
on page 725
[:SOURce<hw>]:IQ:IMPairment:LEAKage:Q
on page 725
Gain Imbalance - I/Q Mod
Sets the imbalance of the I and Q vector (see Chapter 5.7.1.1, "Gain and Gain Imbal-
ance" , on page 289).
The entry is made in dB (default) or %, where 1 dB offset is roughly 12 % according to
the following:
Imbalance [dB] = 20log ( | GainQ | / | GainI |)
Positive values mean that the Q vector is amplified more than the I vector by the corre-
sponding percentage. Negative values have the opposite effect.
Remote command:
[:SOURce<hw>]:IQ:IMPairment:IQRatio[:MAGNitude]
on page 725
Quadrature Offset - I/Q Mod
Sets the quadrature offset (see Chapter 5.7.1.3, "Quadrature Offset" , on page 290).
Remote command:
[:SOURce<hw>]:IQ:IMPairment:QUADrature[:ANGLe]
on page 726
5.6.2.3 I/Q Swap and I/Q Wideband
The I/Q control can be swapped and the optimized setting for wideband signals can be
selected in the middle section of the menu.
I/Q-Swap - I/Q Mod
Selects normal or swapped I/Q control for an external analog signal. The modulation
sidebands are inverted by swapping the I and Q signals.
This parameter enables I/Q modulation to be performed on signals according to
IS2000 (cdma2000 standard) and the majority of all other standards. As a result, an I/Q
demodulator defined according to IS2000 can also be used for demodulating the gen-
erated signals.
I/Q Modulation - I/Q Mod Block