Keysight P9241, Scpi Programmer'S Manual

Page: 448 / 1344

448 Keysight P9241/42/43A Oscilloscopes SCPI Programmer's Guide
21
:MEASure Commands
:MEASure:FFT:ACPR
(see page 1196 )
Command Syntax
:MEASure:FFT:ACPR <chan_width>,<chan_spacing>,<chan>[,<source>]
<chan_width> ::= of main range and sideband channels, Hz in NR3 format
<chan_spacing> ::= spacing between main range and sideband channels,
Hz in NR3 format
<chan> ::= {CENTer | HIGH<sb> | LOW<sb>}
<sb> ::= sideband 1 to 5
<source> ::= {FUNCtion<m> | MATH<m> | FFT} (must be an FFT waveform)
<m> ::= 1 to (# math functions) in NR1 format
The :MEASure:FFT:ACPR command installs an FFT analysis Adjacent Channel
Power Ratio (ACPR) measurement on screen.
Adjacent Channel Power Ratio (or channel leakage ratio) measures the ratio of the
power in the main frequency range to the power contained in one or more
sidebands.
The main range is specified by a channel width and a center frequency. The center
frequency used in the measurement is the one defined for the FFT function.
Sidebands (with the same width as the main range) exist above and below the
main range separated by the channel spacing width.
The sideband used for the measurement is selected with the <chan> parameter.
You can select the first through fifth sidebands above or below the main range
(HIGH1 through HIGH5 above and LOW1 through LOW5 below). The full sideband
must be in the graticule (on screen) to be measured. Otherwise, the measurement
results will be "Incomplete".
When this measurement is tracked with cursors, the cursors show the sideband
being measured.
Query Syntax
:MEASure:FFT:ACPR? <chan_width>,<chan_spacing>,<chan>[,<source>]
The :MEASure:FFT:ACPR? query returns the measured Adjacent Channel Power
Ratio (ACPR) value.
Return Format
<return_value><NL>
<return_value> ::= adjacent channel power ratio, dBV in NR3 format
See Also • ":MEASure:FFT:CPOWer" on page 449
• ":MEASure:FFT:OBW" on page 450
• ":MEASure:FFT:THD" on page 451