Specifies whether to analyze just the real I or Q component of the acquired IQ data, or analyze the complex IQ data.

You do not need to use a selector string to configure or read this property for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals.

The default value is IQ.

Remarks

The following table lists the characteristics of this property.

Short Name Spectrum Analysis Input
Data type ci32.png
Permissions Read/Write
High-level VIs N/A
Resettable Yes
IQ 0

Measurement analyzes the acquired I+jQ data, resulting generally in a spectrum that is not symmetric around 0 Hz. Spectrum trace result contains both positive and negative frequencies. Since the RMS power of the complex envelope is 3.01 dB higher than that of its equivalent real RF signal, the spectrum trace result of the acquired I+jQ data is scaled by -3.01 dB.

I Only 1

Measurement ignores the Q data from the acquired I+jQ data and analyzes I+j0, resulting in a spectrum that is symmetric around 0 Hz. Spectrum trace result contains positive frequencies only. Spectrum of I+j0 data is scaled by +3.01 dB to account for the power of the negative frequencies that are not returned in the spectrum trace.
Q Only 2

Measurement ignores the I data from the acquired I+jQ data and analyzes Q+j0, resulting in a spectrum that is symmetric around 0 Hz. Spectrum trace result contains positive frequencies only. Spectrum of Q+j0 data is scaled by +3.01 dB to account for the power of the negative frequencies that are not returned in the spectrum trace.