Performance Bounds on the Partial Gain to Q-Factor Quotient for Loaded $N$-Port Antenna Systems

A method based on optimizing current distributions using convex optimization to derive the theoretical performance bounds of antenna systems modelled by the method of moments (MoM) is reformulated to those constructed by loaded $N$-port structures. The upper bounds of the partial gain to Q-factor quotient with a given radiation direction and polarization for a lossless rectangular metallic plate are studied in particular. The results reveal good agreement with previous work.