  We give a comprehensive study on regularized approximate electromagnetic
cloaking via the transformation optics approach. The following aspects are
investigated: (i) near-invisibility cloaking of passive media as well as
active/radiating sources; (ii) the existence of cloak- busting inclusions
without lossy medium lining; (iii) overcoming the cloaking-busts by employing a
lossy layer outside the cloaked region; (iv) the frequency dependence of the
cloaking performances. We address these issues and connect the obtained
asymptotic results to singular ideal cloaking. Numerical verifications and
demonstrations are provided to show the sharpness of our analytical study.

Analysis of PDEs;Optics