GB308664A - Improvements in or relating to impedance matching devices suitable for use in high frequency transmission systems - Google Patents

Abstract

308,664. Marconi's Wireless Telegraph Co., Ltd., (Assignees of Lindenblad, N. E.). March 23, 1928, [Convention date]. Coupling oscillating and radiating circuits; drying-out aerials.-High-frequency transmission lines are coupled to each other by connecting each line to symmetrical points on a linear oscillator, the connecting-points being chosen so tHat the impedances of the lines are matched. Condensers are provided to prevent the short-circuiting of direct or low-frequency current that may be sent though the lines for melting sleet deposits &c. As shown in Fig. 1, the input line 2, 4 and the output line 6, 8 are connected to symmetrical points on the linear oscillator 10. Radiation may be reduced by bending the oscillator into U form. Fig. 4 shows such an arrangement with the oscillator duplicated, and with condensers 30 connected at the potential nodes of the oscillators 10, 20. In Fig. 5, the two U-shaped oscillators 10, 20 are connected at their current nodes to form a loop. Fig. 6 shows a practical form of the coupling, with the oscillators 10, 20 forming a loop 40 connected by strain insulators 22 - - 28 to the input line 2, 4 and the branched output line 6, 8. The condensers 30 are formed by overlapping lengths of wire separated by insulation, and one condenser bridge may be adjustable to tune the coupling. Tappings 50, 52 for the input and output lines are adjustable along the oscillator wires. A similar arrangement may be employed for single wire lines (Fig. 7, not shown).