In this mode, the signal generator modulates a continuous wave (CW) signal with an I/Q waveform. I/Q modulation is only available on vector models.
Note: Parameter choices vary by instrument. Some of the parameters listed below might not be available on your particular instrument. The bench application will list only those parameters, and parameter ranges, available for your particular instrument.
To enable I/Q modulation, select the "On" button.
Source – Select the I/Q modulation source.
Correction Optimized Path – Enable the internal optimization path to accommodate I/Q signals.
Internal Phase Polarity – Select the "Normal" or "Inverted" digital phase polarity.
Burst Envelope – Enable or disable the burst envelope function.
Internal Equalization Filter – Enable or disable the internal equalization filter. This filter can be used to correct and/or impair the RF and external I/Q outputs for the internal I/Q source.
Optimize Internal Channel – Select between optimizing the internal I/Q channel for EVM (Error Vector Magnitude) at the expense of ACP (Adjacent Channel Power) or optimizing for ACP at the expense of EVM.
Internal Channel Correction – Enable or disable the RF and baseband magnitude and phase corrections across the 160 MHz baseband bandwidth, at the current frequency.
To enable I/Q adjustments, select the "On" button.
I Offset – Adjust the I channel offset value on the internal baseband generator as a percentage between -20% and +20%.
Q Offset – Adjust the Q channel offset value on the internal baseband generator as a percentage between -20% and +20%.
I/Q Gain – Adjust the ratio of I to Q while preserving the composite, vector magnitude. Adding gain (+x dB) to the signal increases the I component and decreases the Q component proportionally. Reducing gain (–x dB) decreases the I component and increases the Q component proportionally.
Quadrature Angle Adjustment – Adjust the phase angle (quadrature skew) between the I and Q vectors by increasing or decreasing the Q phase angle.
I/Q Phase – Adjust the absolute phase of the internal I/Q channel by rotating both I and Q, and thereby adjusting the relative phase of the RF carrier.
I/Q Skew – Adjust the I/Q skew, which is a time delay difference between the I and Q signals. Equal and opposite skew is applied to both I and Q and affects the RF Output and I/Q output paths simultaneously. A positive value delays the I signal relative to the Q signal; a negative value delays the Q signal relative to the I signal.
I/Q Delay – Set the absolute phase of both I and Q with respect to triggers and markers. A positive value delays I and Q. This value affects both the external I/Q out signals and the baseband signal modulated on the RF output. This adjustment does not affect external I/Q inputs.
External Input I Offset – Set the offset voltage for a signal applied to the external I Input connector.
External Input Q Offset – Set the offset voltage for a signal applied to the external Q Input connector.
External Input I/Q Gain Balance – Set the External Input I/Q Gain Balance in dB.
Quadrature Angle Adjustment – Adjust the phase angle (quadrature skew) between the I and Q vectors by increasing or decreasing the Q phase angle. This parameter adjusts the signals applied externally to the signal generator’s front-panel Q input connector.
Common Mode I/Q Offset – Set the common mode offset voltage for both the in–phase (I) and quadrature–phase (Q) signals going to the rear panel I and Q output connectors.
Differential Mode I Offset – Set the differential offset voltage for an in–phase (I) signal routed to the I output connectors.
Differential Mode Q Offset – Set the differential offset voltage for a quadrature–phase (Q) signal routed to the Q output connectors.