  Using some special properties of a permeability-near-zero material, the
radiation of a line current is greatly enhanced by choosing appropriately the
dimension of a dielectric domain in which the source lies and that of a
permeability-near-zero shell. The radiation of the source can also be
completely suppressed by adding appropriately another dielectric domain or an
arbitrary perfect electric conductor (PEC) inside the shell. Enhanced directive
radiation is also demonstrated by adding a PEC substrate.
