R&S SMJ100A, Operating Manual

Page: 308 / 874

Instrument Function
R&S
®
SMJ100A
292 Operating Manual 1403.7458.32 ─ 14
State - Digital Impairments
Activates/deactivates digital I/Q impairment.
When activated, the settings for carrier leakage, I/Q imbalance and quadrature offset
become effective.
Internal predistortion for compensating the I/Q modulator is not influenced by this set-
ting.
Remote command:
[:SOURce<hw>]:BB:IMPairment:STATe
on page 671
I/Q Offset - Digital Impairments
Sets the carrier leakage (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 leakage completely (offset = 0 percent).
For more information, see Chapter 5.7.1.2, "I and Q Offset" , on page 290.
Remote command:
[:SOURce<hw>]:BB:IMPairment:LEAKage:I
on page 670
[:SOURce<hw>]:BB:IMPairment:LEAKage:Q
on page 670
Gain Imbalance - Digital Impairments
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>]:BB:IMPairment:IQRatio[:MAGNitude]
on page 669
Quadrature Offset - Digital Impairments
Sets the quadrature offset (see Chapter 5.7.1.3, "Quadrature Offset" , on page 290).
Remote command:
[:SOURce<hw>]:BB:IMPairment:QUADrature[:ANGLe]
on page 670
Internal Compensation
Internal compensation of signal distortions of the RF output can be activated / deacti-
vated.
Optimize internal IQ-Impairments for RF Output - Digital Impairments
Activates or deactivates internal compensation of signal distortions of the RF output.
Signal distortions can be either optimized for the RF output (active) or for the differen-
tial I/Q output (not active).
Remote command:
[:SOURce<hw>]:BB:IMPairment:OPTimization:STATe
on page 671
Impairment of Digital I/Q Signal and Noise Generator - AWGN/IMP Block