Research On The Multi-Wavelength Optically Controlled Phased Array Antenna System

The application of fiber and photonic technology to Phased Array Antenna (PAA) systems are gradually becoming a trend in the development of designing radar systems. This new technology has brought great benefits to some research fields such as RF signal distribution and antenna remote control. The most striking characteristic of photonic is its wide instantaneous bandwidths, which reduces transmission loss in the data remote control and decreases the size and weight of the arrays. The inherent drawback of common PAA system is its limited bandwidths. Thus, "beam squint" occurs when the frequency varies in a wide range. This difficulty, however, can be overcome if True-Time-Delay (TTD) network which is made up of fiber and photonic devices is used.The Optically Controlled PAA (OCPAA) system generally falls into three categories: point-to-point transmission system, Time Division Multiplexing (TDM) transmission system and Wavelength Division Multiplexing (WDM) transmission system. WDM system codes phase delay according to the wavelength. This system has a great capacity of contracting hard wares, but requires high quality of optical apparatuses, especially needs narrow line-width multi-wavelength laser, which is much expensive. Therefore, the research of multi-wavelength OCPAA is still demonstrated in laboratory.The main problems concerned in this paper are as follows.-1. On the condition of studying the thesis-concerned knowledge and knowing its background of development, research the tasks to be finished in the thesis on the whole. Thus, the readers can get a general understanding about OCPAA.2. Demonstrate the photonic technology applied to OCPAA system and offer reasons for choice in photonic apparatuses.3. Introduce the working principle of phased-shifter in traditional PAA system. Put much emphasis on the demonstration of the characteristic of none "beam squint" of TTD network in wide instant bandwidth and give several ever-advanced principles of realization of the network.4. Research the structure and realizing principle of one type of multi-wavelength OCPAA system and give the results of simulative measurement of TTD network of 2-b OCPAA system. The results are in accordance with those theoretically, which gains a rather satisfactory result.