  Fundamental bounds on the performance of monochromatic
scattering-cancellation and field-zeroing cloaks made of prescribed linear
passive materials occupying a predefined design region are formulated by
projecting field quantities onto a sub-sectional basis and applying
quadratically constrained quadratic programming. Formulations are numerically
tested revealing key physical trends as well as advantages and disadvantages
between the two classes of cloaks. Results show that the use of low-loss
materials with high dielectric contrast affords the highest potential for
effective cloaking.
