Patent ID: 7772827
Filing Date: 2010-08-10
Classification: G01R

Abstract:
1. Measuring device which can be connected via at least two ports to a device under test, comprising: several excitation units assigned to each port, wherein each excitation unit provides a signal generator, with which the assigned port can be supplied with an excitation signal having a frequency; a phase-measuring device for measuring the actual phase offset between the excitation signals at measurement positions output at the ports; a control device, which varies the frequency of at least one of the two signal generators during a correction interval in such a manner that a specified set phase offset is achieved at reference positions between the excitation signals output at the ports; and a memory device, in which a table is stored with one set phase offset at each of the measuring positions related to a set phase offset at the reference positions between the signals output at the ports for each of several frequencies; wherein the control device registers a deviation of the actual phase offset measured at a given frequency at the measuring positions from the set phase offset at the measuring positions stored in the memory device and increases the frequency of the signal generator lagging in phase during the correction interval and/or reduces the frequency of the signal generator leading in phase during the correction interval, if the actual phase offset is greater than the set phase offset, or respectively reduces the frequency of the signal generator lagging in phase during the correction interval and/or increases the frequency of the signal generator leading in phase during the correction interval, if the actual phase offset is less than the set phase offset, and wherein a large phase offset is measured, a large frequency deviation is initially used which is then reduced stepwise.