Method and network analyzer for measuring group runtime in a measuring object

摘要

A network analyzer for measuring a group delay time, which is caused by a device under test to be measured, generates an excitation signal comprising two signals (xIn1(t),xIn2(t)) spaced by a frequency difference, excites the device with the excitation signal and measures a response signal comprising two signals (xOut1(t),xOut2(t)), which are respectively phase distorted by the device relative to the signals (xIn1(t),xIn2(t)) of the excitation signal. It determines the phase difference (ΔφIn) between the signals (xIn1(t),xIn2(t)) associated with the excitation signal and a phase difference (ΔφOut) between the signals (xOut1(t), xOut2(t)) associated with the response signal. Finally, it calculates the group delay time from the phase difference (ΔφIn) of the signals (xIn1(t),xIn2(t)) associated with the excitation signal, the phase difference (ΔφOut) of the signals (xOut1(t),xOut2(t) associated with the response signal and the frequency difference.

主权项

1. A method for measuring a group delay time (τG), which is caused by a device under test to be measured, with the use of a network analyzer, comprising the following methods steps:
generating within the network analyzer of an excitation signal (xIn(t)) comprising two signals (xIn1(t), xIn2(t)), which are spaced with a frequency difference (Δω) relative to one another; exciting of the device under test with the excitation signal (xIn(t)) and measurement by the network analyzer of a response signal (xOut(t)) comprising two signals (xOut1(t), xOut2(t)), which are each phase-distorted by the device under test relative to the signals (xIn1(t)xIn2(t))of the excitation signal (xIn(t)); determining of a phase difference (ΔφIn)between the signals (xIn1(t), xIn2(t)) associated with the excitation signal (xIn(t)) and a phase difference (ΔφOut) between the signals (xOut1(t)xOut2(t)) associated with the response signal (xOut(t)); and
calculating of the group delay time (τG) from the phase difference (ΔφIn) of the signals (xIn1(t), xIn2(t)) associated with the excitation signal (xIn(t), the phase difference (ΔφOut) of the signals (xOut1(t), xOut2 (t)) associated with the response signal (xOut (t))and the frequency difference (Δω), wherein the device under test is a frequency-converting functional unit, and wherein the signals (xIn1 (t), x2(t)) associated with the excitation signal (xIn(t) are mixed sequentially to the signals (xOut1(t), xOut2(t)) associated with the response signal (xOut(t)) into the intermediate frequency band respective into the base band.