IQ Mod. Quality
(Option UN3, UN4, UN8, or UN9 Only)

Error Vector Magnitude (EVM) is the magnitude of the vectorial difference between the measured signal and an ideal reference signal in the I-Q plane.

Global Phase Error is the magnitude of the phase difference between the measured signal and an ideal reference signal in the I-Q plane.

Shift Error is the magnitude of the frequency difference between the measured signal and an ideal reference signal in the I-Q plane. This is expressed as a % error from the desired frequency shift.

Deviation Accuracy is the magnitude of the frequency difference between the measured signal and an ideal reference signal in the I-Q plane. This is expressed as frequency difference from the desired frequency shift, in Hz.

This test measures the accuracy of the rear-panel I and Q output signals created by the internal baseband generator in Option UN3, UN4, UN8, or UN9 signal generators. The vector signal analyzer is configured to measure the I and Q baseband signals and demodulate each modulation type separately.

Instrument

Critical Specifications for This Test

Recommended Model

Vector Signal Analyzer

none

89441A with Options AYA, AYH, AY7, and AY9

 

Connections and Setup Procedures

All test equipment requires a 30 minute warm-up period to ensure accurate performance.

In the following test setup, direct cable and adapter connections are designated as solid lines. Changeable cable and adapter connections are designated as dashed lines.

 

Connect all test equipment as shown.

  1. Connect GPIB cables to all GPIB-controlled test equipment.

  2. While performing this test, follow all instructions on the controller display.
     

Setup for I/Q modulation quality