Agilent Technologies X Series Programmer's Manual page 24

Introduction to Programming X-Series Applications
SCPI Measurement Commands
where Xi is a data point value, X is the arithmetic mean of the data point values for the
specified region(s), and n is the number of data points in the specified region(s).
Σ
1 _
(|Xi| – X)
SDEV =
n
Xi ∈ region(s)
where |Xi| is the magnitude of an I/Q pair, X is the mean of the magnitudes for the
specified region(s), and n is the number of data points in the specified region(s).
• PPHase - returns the x,y pairs of both rms power (dBm) and arithmetic mean phase
(radian) for every specified region and frequency offset (Hz). The number of pairs is
defined by the specified number of regions. This parameter can be used for I/Q vector
(n=0) in Waveform (time domain) measurement and all parameters are specified by
data point in PPHase.
The rms power of the specified region may be expressed as:
Power = 10 x log [10 x (RMS I/Q value)] + 10.
The RMS I/Q value (peak volts) is:
Σ
1 _
Xi Xi*
n
Xi ∈ region
where Xi is the complex value representation of an I/Q pair, Xi* its conjugate complex
number, and n is the number of I/Q pairs in the specified region.
The arithmetic mean phase of the specified region may be expressed as:
Σ
1 _
Yi
n
Yi ∈ region
where Yi is the unwrapped phase of I/Q pair with applying frequency correction and n is
the number of I/Q pairs in the specified region.
The frequency correction is made by the frequency offset calculated by the arithmetic
mean of every specified region's frequency offset. Each frequency offset is calculated by
the least square method against the unwrapped phase of I/Q pair.
Sample Trace Data - Constant Envelope
(See below for explanation of variables.)
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Chapter 1