Reflection of an open-ended coaxial line and application to nondestructive measurement of materials

With the appearance of low-cost solid-state sources, microwaves provide an interesting tool for the nondestructive testing of various materials, among others, in the field of biomedicai engineering. Reflection measurement techniques require a way to correlate measured reflection factors with the permittivity of the material. This relationship is derived here for the open-ended coaxial line propagating the TEM mode.