Keysight E6640A, Measurement Applications User & Programmer Reference

Page: 201 / 2870

4 Input/Output Functions
Input/Output
Notes This is command only, there is no query
Dependencies Grayed out in the SA measurement.
Backwards
Compatibility SCPI [:SENSe]:FEED:SOURce:STORe
Initial S/W Revision Prior to A.02.00
Corrections
This key accesses the Amplitude Corrections menu.
Amplitude Corrections arrays can be entered, sent over SCPI, or loaded from a file. They allow you to
correct the response of the analyzer for various use cases. The X-series supports four separate
Corrections arrays, each of which can contain up to 2000 points. They can be turned on and off individually
and any or all can be on at the same time.
Trace data is in absolute units and corrections data is in relative units, but we want to be able to display
trace data at the same time as corrections data. Therefore we establish a reference line to be used while
building or editing a Corrections table. The reference line is halfway up the display and represents 0 dB of
correction. It is labeled “0 dB CORREC”. It is drawn in blue.
Corrections data is always in dB. Whatever dB value appears in the correction table represents the
correction applied to that trace at that frequency. So if a table entry shows 30 dB that means we ADD 30
dB to each trace to correct it before displaying it.
In zero span, where the frequency is always the center frequency of the analyzer, we apply the
(interpolated) correction for the center frequency to all points in the trace. In the event where there are
two correction amplitudes at the center frequency, we apply the first one in the table.
Note that the corrections are applied as the data is taken; therefore, a trace in View (Update Off) will not be
affected by changes made to the corrections table after the trace is put in View.
On the RF Input/Output panel, there are two full-duplex RF ports (RFIO1 and RFIO2), RF Input and RF
Output. When RF Input is selected, it will correspond to one input port from two half-duplex RF ports(RFIO3
and RFIO4), and when RF Output is selected, it will correspond to one output port from two half-duplex RF
ports(RFIO3 and RFIO4). So there are 8 sets of corrections in all that can be applied to the RF ports. Ports
cannot share the same set of corrections but a single port can have multiple corrections applied to it. The
correction data is applied to incomming signals as well as transmitted signals and is in the form of a list of
spot frequencies and amplitude correction levels.
Key Path
Input/Output, Corrections
Mode SA, I/Q Analyzer, Phase Noise, VXA, RTSA, EMI Receiver, DVB-T/H, DTMB, DVB-T/H, DTMB, W-
CDMA, LTE & LTE-Adv FDD, LTE & LTE-Adv TDD, Sequence Analyzer, BTooth
Dependencies This key will only appear if you have the proper option installed in your instrument.
Amplitude correction may not be available in all modes; if a mode does not support amplitude
correction, the Corrections key should be blanked while in that mode. If an application supports
corrections but the current measurement does not, then the key should be grayed out in that
measurement
W-CDMA & HSPA Measurement Applications Reference 201