Vectorial Load Pull Process with a 4-Port NWA
The advantage of this procedure is that the complex impedances of the DUT and the circuitry (ZSource, ZIn, Zload, ZOut) are measured for each measurement point with a 4-port network analyzer and directional couplers. This way, extensive data for characterizing the DUT can be captured.
Basically, it is therefore no longer required to perform a characterization of the tuner, since the source and load impedance are determined with the network analyzer during the measurements. Impedance measurements are not necessarily restricted to the fundamental wave; by using network analyzers with the relevant features, it is also possible to expand them to harmonics and broad-band frequency ranges. If measurements are conducted with non-linear network analyzers for example by Keysight, it is possible to measure the characteristics of the harmonics at the same time. Value and phase of the generated, transmitted and reflected fundamental waves and harmonics are also taken into account. The network analyzer which is required for this is called an NVNA (NVNA: Nonlinear Vector Network Analyzer). The generated measurement data are called X parameters. Control and data evaluation is easily managed with the software which is integrated into the tuner.