Series-fed Optical Control Of Phased Array Technology Principle And Simulation Studies

Compared with traditional phased array radar, optically controlled phased array radar has many merits owing to the use of fiber transmission and optical true time delay (OTTD). In this dissertation, the feature and the development of optically controlled phased array radar are involved in and the value and the signification of studying optically controlled phased array radar are mentioned.Optically controlled serially fed phased array system has all the advantages of conventional optically controlled phased array system, yet only requires one tunable laser, one optical modulator, one optical circulator and one Bragg fiber-optic grating to provide OTTD by serially feed according to the pulsed nature of radar. Compared with conventional optically controlled phase array system, optically controlled serially fed phased array system can greatly reduce the price and improve the other performance of the system. In this dissertation, optically controlled serially fed phased array is studied systematically and in detail.First, we state the basic knowledge and principle of optically controlled phase array system and introduce the optical components that are involved in the system as well as the implementing scheme of OTTD of the system. Then, aiming at implementing scheme of OTTD in serially feed, we analyze the technology principle of optically controlled serially fed phased array both in transmit mode and receive mode, based on which, an implementing scheme of OTTD in serially feed that can be used together in transmit mode and receive mode is presented. We also build the vector model of optically controlled serially fed phased array both in transmit mode and receive mode and accomplish the computer simulation of pattern and the LFM pulse compression in ideal condition.According to the model of optically controlled serially fed phased array, we analyze the effect of the non-ideal factors of fiber-optic link and synchronizing timing unit on the pattern and the LFM pulse compression and accomplish the interrelated computer simulation and analysis. The non-ideal factors of fiber-optic link include the fluctuation of the reflecting spectrum of Bragg fiber-optic grating, the optical power fluctuation of tunable laser and the wavelength switching speed of tunable laser. The effect of synchronizing timing unit on the system include the effect of synchronizing timing unit that control the XMIT gates on XMIT gates and the effect of non-synchronous of the tuning signal of the tuned laser on tuned laser. Simulating results indicate that the effect of the non-ideal factors of fiber-optic link and synchronizing timing unit on the pattern and the LFM pulse compression is not serious in current component and technique level. So compared with conventional optically controlled phased array system, optically controlled serially fed phased array system can realize broad instantaneous bandwidth and wide scanning angle more easily.