Realization of a broadband controlled load for a nonlinear system


RF and microwave technology is evolving towards more agile systems, that smoothly adapt to their surrounding environment. This results in more and more demanding design and characterization specifications. The mainstream in the microwave community  is still focusing on fixed termination impedance levels during design, however.
As this hypothesis of constant loading impedance is more and more violated, this calls for a characterization that allows to measure the dependence of the system behavior. The system is then loaded either with a variable  load or with a dynamic load (that changes with frequency). These new operating conditions are much more realistic and are expected to give a better view on the behavior of the system. The information that is obtained is especially useful for a designer, who can tune the design to remain below a certain level of sensitivity on the variation of the load.


Design a measurement setup that allows one to synthesize a broadband impedance with a predefined dynamic profile and that can vary over some range. 


The hart of the setup consists of a (modified) PNA-X network analyzer and an arbitrary waveform generator that has a baseband bandwidth of 4 GS/s.  The idea is to try to  impose the requested impedance profile, first on the fundamental tone and then on the harmonics as well. This will e limited by the capability of the sources. As one wants the impedance profile to be imposed accurately, there will be a need for an iterative procedure that will take measurements in the loop to adapt the excitation such that the impedance profile is indeed present.
Interested? Want to know more? Please feel free to contact the promoter. By asking you dont commit to anything else than getting more information.


Yves Rolain
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