GB679903A - Multi-channel microwave transmission system - Google Patents

Abstract

679,903. Multiplex systems. STANDARD TELEPHONES & CABLES, Ltd. Feb. 9, 1951 [April 1, 1950], No. 3196/51. Class 40 (iv). [Also in Groups XL (b) and XL (c)] A multi-channel microwave transmission system makes use of a hollow multi-path conductor, one path being provided by external waves guided by the outer surface, and one or more other paths provided by waves within the conductor. As shown in Fig. 1, the conductor comprises a hollow wave guide 6 externally coated with insulation 8. One path is afforded by microwaves set up or received within the guide by a co-axial line 10, 11. Another path is afforded by microwaves travelling externally to the guide and set up or received by a coaxial line 12, 13. A flared cylindrical member 2 surrounding the end of the guide facilitates the launching and reception of the waves travelling along the external surface. Instead of employing the radial feed line 12, 13, the external waves may be fed and received by a coaxial line of which the outer comprises an extension of the cylinder 2, and the inner an extension of the guide 6. The insulation may be thickened as it enters the flared horn 7 and may reach the inner surface of the horn, tapering thinner again as it enters the cylindrical section 2, Fig. 2 (not shown). In a further modification, two channels are provided within the guide by a partition running lengthwise, Figs. 5 and 6 (not shown). In Fig. 3, an axial central rod 28 and a coaxial cylinder 29 are provided within the hollow conductor 27, thus affording two coaxial pairs 28, 29 and 29, 27 in addition to the surface waves external to the conductor 27, the latter being set up by association with a wave-guide 34.