GB1207491A - Improvements relating to transmission line systems - Google Patents

Abstract

1,207,491. Waveguides; co-axial liners. H. E. M. BARLOW. 6 Oct., 1967 [7 Oct., 1966, 1 Feb., 1967], Nos. 45014/66 and 4818/67. Headings H1A and H1W. A decrease in attenuation is effected by increasing the surface reactance of one of the conductors of a two-conductor transmission line. Such treatment promotes wave propagation in a hybrid mode which is partly a TEM mode and partly a surface-wave mode having the configuration shown. It is stated that the surface reactance may be so chosen that the zero of the electric field approaches one of the conductors very closely and that, under these conditions, the attenuation approaches a minimum. As shown, the inner conductor 1 is coated with a material of high dielectric constant e.g. TiO 2 . The material may be in powder form and may be contained within a thin dielectric envelope. The surface reactance may alternatively be increased by grooving one of the conductors. The invention may be applied to A.C. power lines using two parallel conductors. The surface reactance of one of them is increased by covering it with annular beads of ferrite.