  We propose a class of line-transformed cylindrical cloaks which have
easily-realizable constitutive parameters. The scattering properties of such
cloaks have been investigated numerically for both transverse-electric (TE) and
transverse-magnetic (TM) incidences of plane waves. A line-transformed
invisibility cloak with a perfectly electric conducting (PEC) inner boundary is
actually a reshaping of a PEC line to which the cloaked object is crushed. The
numerical results of near-field distributions and far-field scattering
properties have verified the above conclusions. We also investigate the
relationship between the constitutive parameters of a line-transformed cloak
and the length of the corresponding line. The changing range of constitutive
parameters is large when the line is short, while the changing range becomes
small when the line is long. The above conclusion provides an efficient way to
realize the invisibility cloaks using artificial metamaterials.
