Stanford Research Systems SR780, Operating Manual And Programming Reference

Page: 102 / 497

2-20 Views
SR780 Network Signal Analyzer
Views
Each measurement has an associated view. A view is a way of looking at the complex
measurement data.
Log Magnitude
Log magnitude view graphs the log of the magnitude of the measurement data. The
magnitude is
√
(x
2
+ y
2
) where x is the real part and y is the imaginary part. The Y axis of
the display is logarithmic in scaling.
Linear Magnitude
Linear magnitude view graphs the magnitude of the measurement data. The magnitude is
√
(x
2
+ y
2
) where x is the real part and y is the imaginary part. The Y axis of the display is
linear in scaling.
Magnitude
2
Magnitude
2
view graphs the magnitude squared of the measurement data. The magnitude
squared is (x
2
+ y
2
) where x is the real part and y is the imaginary part. The Y axis of the
display is linear in scaling.
Real Part
Real Part view graphs the real part of the measurement data. The Y axis of the display is
linear in scaling.
Imaginary Part
Imag Part view graphs the imaginary part of the measurement data. The Y axis of the
display is linear in scaling.
Real measurement data, such as baseband time record, have zero imaginary part. This
view is zero for all points.
Imaginary data arises from the multiplication of the input time data by sine and cosine
(heterodyne). Signals in phase with cosine result in real data, signals in phase with sine
result in imaginary data. The real and imaginary parts represent data 90 degrees out of
phase.
Phase
Phase view graphs the phase of the measurement data. The phase is a four-quadrant
quantity defined as
θ
= arctan(y/x) where y is the imaginary part and x is the real part and
y is positive. If y is negative, the phase is negated. Phase is graphed linearly from -180 (-
π
) to +180 (
π
) degrees (radians). To show unwrapped phase, choose the Unwrapped
Phase view.
Real measurement data, such as baseband time record, have zero imaginary part. The
phase is zero for all points.
Single channel phase is relative to the center of the time record for Uniform, BMH,
Hanning, Flattop and Kaiser windows. For Force and Exponential windows, phase is
relative to the start of the time record. For User windows, the Window Form is user