Pulse forming lines for square generators

Abstract

Summary form only given, as follows. There are two reasons for using pulse forming lines (PFL): one is storing the exact amount of energy required for a pulse and the other is discharging this energy into the load in the form of a pulse with a specified pulse shape. The designing of square pulse generators using PFLs made up of identical L and C, are reviewed. 14 different types of PFL were analyzed, utilizing PSpice simulation results. Theses PFLs were characterized with respect to their distinct features: the number of forming lines (single or double), the circuit relationship of the PFL and load (parallel of series), the types of energy storage (current source, voltage source or a combination of both). The characteristic impedance, output parameters such as pulse width, voltage and current magnitudes, and power were derived for each scheme. The merits and demerits of the output parameters were also included. Two features are summarized. Firstly, for the single PFLs, the power delivered to a load can be two times different depending on the topology. Secondly, in the case of double PFLs, the output pulse voltage can be four times different. The choice of the best possible PFL for a given application still remains to be discussed. The PFL with current sources have importance advantages. But, so far the availability of a suitable switch with adequate lifetime and capable of high power operations, remains a problem available. Only some semiconductor switches such as MOSFETs, IGBTs, GTOs,and IGCTs can be used in limited low power applications.