Real vs. Imag (Trace Format)

Real vs. Imag is an x-y plot of the complex trace data similar to the IQ trace format with the Real values on the x-axis and Imaginary values on the y-axis. However, there are several differences between Real vs. Imag and the IQ trace formats.

The first difference is that Real vs. Imag provides three different ways to transform the coordinates of the trace. The transform can be applied separately for the x and y axes using the X Axis Format and Y Axis Format parameters.

The second difference is that the scaling per division can be set separately for each axis (IQ and Const trace formats require the same scaling for both axes). See X Per Division and Y Per Division.

Lastly, in contrast to the IQ trace format, where the type of data typically plotted contains complex numbers whose real and imaginary values are equivalent (voltage values for I and Q), the type of data plotted using the Real vs. Imag format is generally complex stimulus-response data like AM/PM and Gain Compression. For these particular Graph trace data types, the x-axis shows stimulus voltage and the y-axis shows differential phase or gain, respectively.

Since the underlying data that is plotted is just an array of complex numbers, this trace format can be used with other types of data (such as an IQ Meas Time trace for Digital Demod). However, the main use of this trace format is for Graph traces where the real and imaginary values for each point do not have the same interpretation.