Photoconductive Switch Pulse Source Circuit Analysis And A Slow Decay For Theoretical Research

Photoconductive Semiconductor Switches(PCSS)have a very broad prospect of applications in numerous fields such as the generation of high power ultra-wideband (UWB)pulses and ultra-fast electronics because of their excellent characteristic. GaAs PCSS have many advantages over others in response speed,the transfer efficiency of light into electricity and high voltage resistant,especially they can operate in a nonlinear mode with high gain which can reduce the triggering optical energy by 3-5 orders of magnitude comparing to the conventional linear mode. This makes it realistically possible to realize the miniaturization,practicality and integration of the system of PCSS。This paper summarized pre-used ultra-wideband source circuit using PCSS, and the exhaustive theoretic analysis of traditional Auston circuit and pulse-forming circuit is presented. The latter bears some outstanding advantages: easy-production ,great power capability ,and longer longevity of the switch. Ideally, the voltage's transmission efficiency of Blumlein can reach to 100 percent, which is two times of the single pulse-forming line's, so it will be applied widely in ultra-wideband source circuit. The software Pspice is utilized to give the transient analysis of the pulse-forming network: the circuit models of two type pulse-forming network are given and the output profile is worked out. The results is the same to the analytical analysis, but the procedure is easier. In order to realize the simulation of the ultra-wideband source circuit using PCSS, the time-domain model of PCSS is summarized. The linearity mode of PCSS can be modeled in Pspice using a time-varying resistance, the non-linearity mode only can be realized using numerical analysis.The research of electromagnetic missile and the slow-decay effect is the advanced task of the electromagnetism, which can be widely used in many fields: ultra-wide radar, ultra-wide secrecy communication ,high-power microwave and etc. The detailed analysis of the slow-decay effect of pulse propagation is presented in this paper. The character of radiation of disk radiator is analyzed with transfer function in frequency domain. Near or far field and law of energy propagation are presented at axes of disk. Time domain electromagnetic waves are analyzed in detail by defining a energy radiation parameter. The nature is as same as sinusoidal electromagnetic wave. They can decrease much more slowly because the radiating capacity of high frequency is better than the low, then coincident understand can been reached between them.