3. I/Q

IQ Adjustments

Choice: On | Off

Default: Off

Double-click or use the drop-down menu to turn the I/Q adjustments on or off.

• On − the values entered for I and Q parameters are applied to the I and Q signals.

• Off − I/Q adjustment values are not applied to the I and Q signals.

I Offset

Range:

ESG/PSG: –50% to 50%

EXG/MXG: –20% to 20% 

Default:

0.00% 

Set I/Q Adjustments to On to enable this parameter.

Enter a DC offset value to apply to the I signal before the I/Q modulator. Use this offset to remove imperfections in the in-phase signal or to introduce calibrated impairments.

For standard I/Q, this sets an origin offset for standard in-phase signals. An offset of 100% is equivalent to 500 mV DC at the front panel I input connector. The offset is used to remove imperfections in the in-phase signal or to introduce calibrated impairments.

When using this setting to minimize the LO feedthrough signal, optimum performance is achieved when the adjustment is made after any other I/Q path adjustments. If other adjustments are made after minimization is performed, the LO feedthrough signal may increase.

Q Offset

Range:

ESG/PSG: –50% to 50%

EXG/MXG: –20% to 20% 

Default:

0.00% 

Set I/Q Adjustments to On to enable this parameter.

Enter a DC offset value to apply to the Q signal before the I/Q modulator. Use this offset to remove imperfections in the quadrature-phase signal or to introduce calibrated impairments.

This cell adjusts the amplitude level of the quadrature-phase signals. The setting appears as a percentage of full scale for standard I/Q and as an offset voltage for wideband I/Q.

When using this setting to minimize the LO feedthrough signal, optimum performance is achieved when the adjustment is made after any other I/Q path adjustments. If other adjustments are made after minimization is performed, the LO feedthrough signal may increase.

I/Q Gain Balance

Range: for specified range values, see the signal generator's data sheet

Set I/Q Adjustments to On to enable this parameter.

Enter a gain ratio, by which I gain exceeds Q gain.

For example, if you enter a value of 1 dB, the I signal will have 1 dB more amplitude than the Q signal. Use the gain balance to remove imperfections in I and Q or introduce calibrated impairments.

Quadrature Angle Adjustment

Range: –10 to 10 degrees

Default: 0.00 degrees

Set I/Q Adjustments to On to enable this parameter.

Enter a value to adjust the Q phase angle. When the quadrature skew is zero, the phase angle between the I and Q vectors is 90 degrees. Positive skew increases the angle from 90 degrees while negative skew decreases the angle from 90 degrees.

I/Q Timing Skew Path

Choice: RF | Baseband (BB)

Default: RF

Set I/Q Adjustments to On to enable this parameter.

Double-click or use the drop-down menu to select whether the path is RF or Baseband (BB).

I/Q Correction Optimization Path

Choice:

N5172B/N5182B: RF Output | External I/Q Output | Dig Bus Output

Other Models: RF Output | External I/Q Output

Default: RF Output

Set I/Q Adjustments to On to enable this parameter.

Double-click or use the drop-down menu to select the I/Q Correction optimization path.

I/Q Skew

Range:

ESG/PSG: –2.0 to 2.0 seconds, in 1 ps steps

EXG/MXG: –800 to 800 ns, in 1 ps steps

Default:

0.0 seconds 

Set I/Q Adjustments to On to enable this parameter.

This cell inputs skew changes to the I and Q paths, in picoseconds. A positive value delays the I signal relative to the Q signal, and a negative value delays the Q signal relative to the I signal.

I/Q Delay

Range: –1.0 to 1.0 seconds

Default: 0.0 seconds

Set I/Q Adjustments to On to enable this feature.

This cell sets the I/Q delay from triggers and markers, in picoseconds.