  Based on a simple model of ground-plane cloaking, we argue that the diffculty
of cloaking is fundamentally limited by delay-loss and delaylbandwidth/size
limitations that worsen as the size of the object to be cloaked increases
relative to the wavelength. These considerations must be taken into account
when scaling experimental cloaking demonstrations from wavelength-scale objects
towards larger sizes, and suggest quantitative material/loss challenges in
cloaking human-scale objects.
