This paper presents frequency domain conditions to analyze H-2, performance
in the worst case over structured uncertainty in the system. These conditi
ons are convex feasibility tests in terms of Linear matrix inequalities acr
oss frequency, of the same nature as tests available for robust stability o
r H-infinity performance. By introducing a deterministic generalization of
the H-2 criterion, the different versions of this test are characterized as
necessary and sufficient for robust performance under corresponding classe
s of dynamic uncertainty.