Agilent Technologies X Series Manual page 491

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.)
–
2
vsd27-8
vsd27-9
vsd27-10
Meas
491