Synthesis of purely dielectric transient lenses

It is shown that the generalized form of a TEM plane wave involving inhomogeneous constitutive parameters can be used for the formal fields for synthesizing lens designs based on differential-geometric scaling. This will allow one to have purely dielectric lenses (with free space permeability), and will provide an extra degree of freedom in lens design. It is also shown that guided TEM waves can be propagated in inhomogeneous isotropic media with permittivity proportional to /spl Psi//sup -2/, where /spl Psi/ is the cylindrical radius. Also, very general conductor cross sections can be specified, which allows for the construction of dispersionless bends in high-voltage transmission systems in which the pulse rise time is small compared to transit times across the transmission line (e.g. coax) cross section, a matter of importance for applications in high-power pulse generation and antenna design and for low-loss transmission lines.