I+jQ Measurement Tips

The following are tips in making I+jQ (C1+j*C2) and Dual I+jQ (C1+j*C2, C3+j*C4) measurements.

Span: The maximum frequency span the VSA can measure is double the single channel span.
Range: For accurate results, the same configuration for the VSA Channel 1 and 2 inputs MUST be used for I+jQ (C1+j*C2). In other words, the Range and Analog Input settings MUST be identical for both channels (see "All" in Logical Channel and Couple Paired Channels).
Coupling: Selecting I+jQ (C1+j*C2) automatically selects DC coupling for both input channels. Use DC coupling because AC coupling creates a notch in the middle of the spectrum. Furthermore, AC coupling causes larger errors in most digitally demodulated measurements.