GB574133A - Improvements in or relating to circuit arrangements for generating electrical waveforms - Google Patents

Abstract

574,133. Impedance networks. BLUMLEIN, D. (Representative of Blumlein, A. D.). June 17, 1942, Nos. 8337, 10213, and 10214. [Classes 40 (iii) and 40 (v)] A stepped wave or an impulse is fed to the ordinary input terminals of a properly terminated delay network and the voltage resulting across the series elements is utilized as shown in Fig. 1. Alternatively, the current in all the shunt elements may pass through the output circuit. In a modification of the latter system, Fig. 3, the network has a double termination and the shunt elements are split. By making the sections of suitable sizes a response corresponding to a desired kind of filter network can be obtained by a method analogous to that described in Specification 517,516. The output may include a component obtained from' the potential drop in the terminating resistance. The input and output circuits may be interchanged. The networks may be used for generating impulses, for example a stepped wave may be applied to a network like that in Fig. 1 in which the series elements on the side from which the output is taken increase and then decrease, the characteristic impedance remaining constant by the provision of a corresponding decrease and then increase of the elements on the other side. An impulse as shown in Fig. 5 is then produced. Impulses with negative portions may be obtained by means of inductive couplings with the series elements or by combining the outputs of two networks to which the input is fed in opposite phase. In another group of arrangements for generating impulses, the sections are uniform but the delay network is misterminated so that voltage impulses produced by interference between the original wave and the reflected wave are obtained at output terminal connected across series elements of a delay network or current impulses are obtained in a load connected at 9, 10, Fig. 8, through which the currents in all the shunt elements flow. With the shunt elements connected to both sides of the output circuit, impulses with positive and negative portions are produced. Another arrangement, Fig. 6, produces a voltage impulse as shown in Fig. 7 at terminals 9, 10.