Section: New Results

Unambiguous de-embedding of filters

Participants : Matthias Caenepeel, Martine Olivi, Fabien Seyfert.

This work was conducted in collaboration with Yves Rolain (VUB, Brussels, Belgium)

Coupling topologies that admit multiple realizations may lead to ambiguous de-embedding tuning procedures where distinct coupled resonator circuits are identified from the same measurements. This is for example the case of the well-known coupling topologies in triplets, quadruplets and extended boxed. If no additional measurements are performed on the DUT (device under tuning), the different solutions to the coupling matrix synthesis problem are undistinguishable, as they yield similar scattering responses. We therefore studied specific tuning strategies to discriminate among them. The later uses a sequence of measurements of the DUT, obtained after varying some discriminating tuning parameters of the filter and testing for coherence of the extracted circuits. This work was presented by Matthias Caenepeel at IMS 2015 in Phoenix [15] and at the EuMC 2015 in Paris [16] . In a similar vein Matthias is currently developing techniques taking advantage of the differential information provided by EM solvers in order to compute the Jacobian matrix of the identified coupling matrix(ces) with respect to the geometrical parameters of the filter.