Keysight N9927-90001 User’s Guide                95
NA (Network Analyzer) Mode
NA Mode Settings
—Imaginary Displays only the reactive portion of the measured complex 
data. The Y-axis is Unitless.
—Z Magnitude
 Displays the effective impedance in ohms.
—Unwrap Phase
 Same as Phase, but without 180 degree wrapping.
Frequency Range
Set the range of frequencies over which you would like to make measurements.
When the frequency range is changed after a calibration is performed, the cal 
becomes interpolated. Learn more in “Interpolation *” on page 140.
How to set Frequency Range
This can be done in two ways:
—Press Freq/Dist
— Then choose from the following:
— Start
 and Stop frequencies – Specify the beginning and end of the 
sweep. 
— Center
 and Span frequencies - Specify the center frequency and 
span of frequencies (half on either side of center).
— Follow each by entering a value using the numeric keypad, the   arrows, 
or the rotary knob.
— After using the   arrows or the rotary knob, press Enter
. The increment 
setting of the arrows is based on the current span and can NOT be changed 
in NA Mode.
— After using the keypad, select a multiplier key. Learn more in “Multiplier 
Abbreviations” on page 43.
Scale Settings
Adjust the Y-axis scale to see the relevant portions of the data trace. The Y-axis 
is divided into 10 graticules. 
This setting can be changed at any time without affecting calibration accuracy.
Phase is unwrapped by comparing the phase from one data point to the 
next. If the phase difference between two data points is greater than 180 
degrees, or if the phase of the first data point is greater than 180 degrees 
from DC, than the phase measurement is probably NOT accurate. To 
ensure that the phase measurement is accurate, increase the resolution 
setting. When making a narrow band measurement, reduce the start 
frequency for the unwrapped phase measurement to ensure the first data 
point is less than 180 degrees from DC.