  We investigate a general class of electromagnetic devices created with any
continuous transformation functions by rigorously calculating the analytical
expressions of the electromagnetic field in the whole space. Some interesting
phenomena associated with these transformation devices, including the
invisibility cloaks, concentrators, and field rotators, are discussed. By
carefully choosing the transformation function, we can realize cloaks which are
insensitive to perturbations at both the inner and outer boundaries.
Furthermore, we find that when the coating layer of the concentrator is
realized with left-handed materials, energy will circulate between the coating
and the core, and the energy transmits through the core of the concentrator can
be much bigger than that transmits through the concentrator. Therefore, such
concentrator is also a power flux amplifier. Finally, we propose a spherical
field rotator, which functions as not only a wave vector rotator, but also a
polarization rotator, depending on the orientations of the spherical rotator
with respect to the incident wave direction. The functionality of these novel
transformation devices are all successfully confirmed by our analytical full
wave method, which also provides an alternate computational efficient
validation method in contrast to numerical validation methods.
