Keysight x-series User Manual

3 Spectrum Analyzer Mode
3.2 Swept SA Measurement
Pwr Avg (RMS)
All filtering and averaging processes work on the power (the square of the
magnitude) of the signal, instead of its log or envelope voltage. This scale is best for
measuring the true time average power of complex signals. This scale is sometimes
called RMS because the resulting voltage is proportional to the square root of the
mean of the square of the voltage.
In the equation for averaging on this scale (below), K is the number of averages
accumulated. (In continuous sweep mode, once K has reached the Average/Hold
Number, K stays at that value, providing a running average.)
New avg = 10 log ((1/K)((K–1)(10
Old avg/10
)+10
New data/10
))
This equation assumes all values are in the decibel scale.
Voltage Avg
All filtering and averaging processes work on the voltage of the envelope of the
signal. This scale is good for observing rise and fall behavior of AM or pulse-
modulated signals such as radar and TDMA transmitters, but its response to noise-
like signals is 1.049 dB lower than the average power of those noise signals. This is
compensated for in the Marker Noise function.
In the equation for averaging on this scale (below), K is the number of averages
accumulated. (In continuous sweep mode, once K has reached the Average/Hold
Number, K stays at that value.)
New avg = 20 log ((1/K)((K–1)(10
Old avg/20
)+10
New data/20
))
This equation assumes all values are in the decibel scale.
Meas Setup Summary Table
Lets you view and access many of the parameters in the Meas Setup menus on one
screen.
Auto Couple
Immediately puts all Auto/Man functions into Auto. Auto Couple is confined to the
current measurement only. It does not affect other measurements in the Mode.
In the Auto state, Auto/Man functions are said to be “coupled”, meaning their values
change as you make changes to other values in the measurement. This helps ensure
accurate measurements and optimum dynamic range. Auto Couple is an immediate
Spectrum Analyzer Mode User's &Programmer's Reference 385

Keysight x-series Specifications

General

Analysis Bandwidth	Up to 1 GHz (depending on model)
Real-Time Bandwidth	Up to 1 GHz (depending on model)
Form Factor	Benchtop
Connectivity	LAN, USB, GPIB
Resolution Bandwidth	1 Hz to 10 MHz (depending on model)