Baseband identification and RF validation of a nonlinear feedback model for a crystal detector

In this work the identification and validation of a block-structured nonlinear Wiener system, that is captured in the feedback path of a closed-loop system, is studied. The technique is applied to the identification of a crystal detector. First, nonparametric initial estimates are generated for the linear dynamic blocks and the static nonlinear system. Next, a parametric model is identified. The extracted model is then validated using microwave measurements performed on the crystal detector. This requires the solution of the differential equation corresponding to the physical representation of the identified model.