Electromagnetic theory of the leaky coaxial cable

The transfer of electromagnetic fields through a grid made of conducting strips similar to the braid of a coaxial cable is expressed by means of a transfer surface impedance relating the tangential electric field to the discontinuity of the tangential magnetic field. This impedance is calculated as a function of the grid parameters. It is then used to establish the electromagnetic theory of a braided coaxial cable located along the axis of a perfectly conducting cylinder. This leads to the existence of two uncoupled modes having the main part of their energy confined on one side of the sheath, with leakage on the other side. This result is compared with the classical coupled line theory.