Research of Indirect Method of Measuring the Pulse Generator Output Resistance by the Step Recovery Diode

Abstract

Paper describes the research on the output resistance of the nanosecond pulse generator built on a Step Recovery Diode. Such generators are used as sources of short (tenths of a nanosecond) pulses. The latter are the basis for: measuring instruments, impact excitation of ultra-wideband antennas of radar sensors, radar of underground sounding and other purposes. To enable a comprehensive analysis of elements the system of differential algebraic equations is solved. The Equations are written for Kirchhoff's laws, describing the “behavior” of currents and voltages of discrete circuit elements, and the parasitic inductors and capacitors also. This is caused by strong influence of parasitic components on transients in the circuit, operating in the time range of less than a nanosecond, which is equivalent to the gigahertz frequencies and higher. The obtained solutions made it possible to reveal the influence of the nominal values of the generator circuit elements on its output resistance. Adjusting the output resistance of the generator to a value close to the characteristic resistance of the line, through which the pulses of the generator are transmitted to the load, maximize the transmission of power to the load and eliminate masking of the useful signal by pulses of re-reflections in the line.