Transient Pulses Of High Power Photoconductive Switch-based Antenna System

In the process of microwave source solid-stating, high-power microwave source technology has a rapid development based on semiconductor materials.This kind of source has three important characteristics: 1) output a narrow pulse signal.2) the output signal with bandwidth Spectrum.3) large transient peak power output.This high-power microwave source has a very broad application prospects in many fields based on these features, in the anti-stealth radar, through-wall radar, ground penetrating radar, large-scale long-range precision ranging, high-power microwave weapon, medical, photography and other fields.However, commonly used electrical parts and the antenna feed structure are too intensive to be able to work in high-power conditions.The main problem is that, the peak power of transmitted signal is big in the case of high-power: up to more than 120MW, peak voltage is very high: at least a few thousand volts, high up to ten thousand volts or more.under such conditions, usually difficulties faced by the system are all parts of the system between the isolation of poor, the discharge between the various parts is difficult to overcome.It is obviously that designing Antenna System with resistant hypertension, radiation properties of a good, low cost, small form , has a great significance to the development and utilization of such a microwave source.Selection and design resistance high-voltage antenna that can fully use the high power source, the high voltage resistance characteristic design of feeding structure and antenna are the focus and the difficult in this article.In this paper, after a detailed analysis of the feature of the semiconductor the microwave source, in order to take full advantage of microwave sources for the purpose of targeted design of antenna system has specific requirements, the fllowing research work is also under the guidance of the request to begin.According to design requirements, the whole job is divided into the following sections: antenna selection and design, active high-power-fed electric design and passive high-power-fed design, the course of the study process methodology has theoretical analysis, EDA simulation, experiments .In the selection and design of high-power antenna process: after comparing the characteristics of various antennas, under the premise permit conditions, selected facial Vivaldi antenna as a radiator.During the desgning ,the effect of dielectric materials, graded line, antenna surface structure to the antenna performance are analysised, study the effect of a variety of grooves on the antenna to its characteristics fistly, in the feed design process: an analysis of a variety of different surface-fed Vivaldi antenna characteristics of the way and eventually made two high voltage electric feed-forward structure, they are: 1) non-equilibrium Blumlein structure of the active feed .2) the different passive coplanar waveguide feed structure.