GB820212A - Improvements relating to electrical waveguide systems - Google Patents

Abstract

820,212. High-frequency impedance networks. GENERAL ELECTRIC CO. Dec. 14, 1955 [Dec. 14, 1954], No. 35911/55. Class 40 (8). A device for transferring a small part of the energy transmitted by a waveguide to an auxiliary circuit, e.g. for measuring its power or frequency, comprises a transmission line 7, Fig. 1, formed by a conducting strip 8 spaced by dielectric material 12 from a wall of the waveguide 1, and receiving energy through at least one slot 5 in the waveguide wall. The line 7 has a right-angled extension 10 to provide an impedance match when coupled to the coaxial line 9 which connects with the measuring circuit 4. Energy is propagated through the waveguide 1 from a source 2 to a load 3, e.g. an antenna, and the slots 5 are arranged to transfer energy received from the source 2 and direct it towards the circuit 4, whilst directing any energy reflected by the load 3 towards a power absorption device 14. Alternatively the device 14 may be replaced by an arrangement, similar to the extension 10 and line 9, coupled to a circuit for examining the energy reflected from the load 3, and, if desired, for comparing the reflected and transmitted energies to obtain the standing wave ratio of the system. In another embodiment, Fig. 2 (not shown), the line 7 is bent to form an extension 10 which is perpendicular to a wide wall of the waveguide. In a further embodiment, Fig. 3 (not shown), the line 7 is not provided with a right-angled extension, and the line 9 is coupled to the strip 8 through an aperture in a conducting block extending across the waveguide. In an alternative construction, Fig. 4 (not shown), the strip 8 is disposed between two layers of dielectric material secured to a wide wall of the waveguide by an outer conducting sheet and clamping bolts. Fig. 5 illustrates a circular waveguide 25 having two transmission lines secured thereto at circumferentially spaced points. Each transmission line comprises a conducting strip 8 disposed between dielectric sheets 20, 22, and an outer conducting plate 21. Energy is transferred through holes 29, 31 in the waveguide wall and the signals received by the two transmission lines may be compared for determining the polarization of the energy propagated in the waveguide.