Network internal signal feedback and injection: Interconnection matrix redesign

The design of systems defined as networks (interconnections) of identical subsystems emerges as an interesting engineering problem, with some open issues. One of these issues is how to "retune" the interconnection in order to ensure the stability and the performance of the system. Based on the LFT representation and on the input-output framework, we propose in this paper some efficient "retuning" methods using convex optimization involving LMI constraints. The proposed approach can be interpreted as an extension of usual state space methods. Its application is investigated for the design of a network of PLLs.