I/Q Path - Keysight x-series User Reference Manual

4 Input/Output Functions
Input/Output
INPut<1|2>:IQ:TYPE I | Q | IQ
INPut<1|2>:IQ:IMPedance LOW | HIGH
Not Supported:
INPut<1|2>:SELect AIQ | RF
TRACe<1|2>:IQ:DATA:FORMat COMPatible | IQBLock | IQPair>
TRACe<1|2>:IQ:DATA:MEMory? <offset samples>,<# of samples>
TRACe<1|2>:IQ:DATA?
TRACe<1|2>:IQ:SET <filter type>,<rbw>,<sample rate>,<trigger source>,<trigger slope>, <pretrigger
samples>, <# of samples>
TRACe<1|2>:IQ:SRATe 10.0kHz to 81.6MHz
TRACe<1|2>:IQ[:STATe] ON|OFF
The Rohde & Schwarz FMU has the following SCPI, which is not supported (these commands start/abort
the probe calibration procedure, which is manually interactive from the front panel):
CALibration:ABORt
CALibration:PROBe[:STARt]

I/Q Path

Selects which I/Q input channels are active. The LED next to each I/Q input port will be on when that port is
active.
The analysis bandwidth for each channel is the same as that of the instrument. For example, the base
N9020A has a bandwidth of 10 MHz. With I/Q input the I and Q channels would each have an analysis
bandwidth of 10 MHz, giving 20 MHz of bandwidth when the I/Q Path is I+jQ. With option B25, the available
bandwidth becomes 25 MHz, giving 25 MHz each to I and Q and 50 MHz to I+jQ.
I/Q voltage to power conversion processing is dependent on the I/Q Path selected.
• With I+jQ input we know that the input signal may not be symmetrical about 0 Hz, because it has a
complex component. Therefore, above 0 Hz only the positive frequency information is displayed, and
below 0 Hz only the negative frequency information is displayed.
• With all other Input Path selections, the input signal has no complex component and therefore is always
symmetrical about 0 Hz. In this case, by convention, the power conversion shows the combined voltage
for both the positive and negative frequencies. The information displayed below 0 Hz is the mirror of the
information displayed above 0 Hz. This results in a power reading 6.02 dB higher (for both) than would be
seen with only the positive frequency voltage. Note also that, in this case the real signal may have
complex modulation embedded in it, but that must be recovered by further signal processing.
Key Path
Remote Command
Example
160
Input/Output, I/Q
[:SENSe]:FEED:IQ:TYPE IQ|IONLy|QONLy
[:SENSe]:FEED:IQ:TYPE?
Set the input to be both the I and Q channels, combined as I + j * Q.
EMI Receiver Mode Reference