Agilent Technologies Signal Analyzer N9030a - Manual (Page 594)

6 RLC Swept SA Measurement Front-Panel & SCPI Reference
Input/Output
calibrated together. The probe calibration is done for a specific channel (I or Q). If in Single-
Ended mode, only the main port is calibrated. When in Differential Input mode, the user is guided
through calibrating both main and complementary ports.
The front panel I/Q port LEDs indicate the current state of that port. On (green) indicates it is
active, and off (dark) indicates it is not in use. For example, the Cal Out port LED is on if and
only if there is signal coming out of that port.
The input is a context and some parameters have separate values for each context. The SCPI for
these parameters has an optional "[:RF|IQ]" node. If the specific context is omitted, the command
acts on the current input context's value. Here are the parameters that are input context sensitive:
l
Center Frequency
l
Trigger Source
It is important to distinguish between the I and Q input ports and the displayed I and Q data
values. The I and Q input ports feed into a digital receiver that does digital tuning and filtering.
The I and Q data seen by the user (either on the display or through SCPI) corresponds to the real
("I") and the imaginary ("Q") output from the digital receiver. When the input path is I+jQ or I
Only and the center frequency is 0 Hz the I input ends up in as the real output from the receiver
and appears as "I" data. Likewise, when the input path is I+jQ and the center frequency is 0 Hz,
the Q input ends up as the imaginary output from the receiver and appears as "Q" data. However,
when the input path is Q Only, the Q input is sent to the receiver as Q+j0, so the receiver output
has the Q input coming out on the real output, and so in Q Only, the signal from the Q input port
appears as the "I" data. Another situation where the I and Q data do not necessarily correspond
directly to the I and Q inputs is when the center frequency is non-zero. The digital processing
involved in the tuning is a complex operation. This will result in I Only data appearing as both "I"
and "Q" data, the same as that signal would appear if seen through the RF input port.
Baseband I/Q Remote Language Compatibility
For the Agilent E4406A VSA Series Transmitter Tester, Option B7C provided baseband I/Q inputs.
Code compatibility has been provided to allow many of the commands for option B7C to function
properly with the X-Series. The X-Series has hardware differences and additional capabilities
(e.g., E4406A does not have independent settings of I & Q nor does it provide for probe
calibrations) which make 100% compatibility impossible.
The following commands are supported:
l
:CALibration:IQ:FLATness
l
:INPut:IMPedance:IQ U50|B50|U1M|B1M
l
:INPut:IMPedance:REFerence <integer>
594 Remote Language Compatibility Measurement Application Reference