Some new bounds related to output feedback pole placement

A number of new results regarding linear output feedback compensation are presented. In particular, it is shown that the rank of an appropriately defined real matrix Ω represents an upper bound on the number of closed-loop poles which can be completely and arbitrarily assigned via constant gain output feedback. A new bound on the minimum number of dynamical elements required for complete and arbitrary closed-loop pole placement is also defined in terms of the observability index of a certain single-input system.