微波光子学主要研究微波和光波的相互作用,其应用领域有宽带无线接入网、传感网络、雷达、卫星通信、仪器仪表和现代电子战等。微波光子技术的优势主要体现为:载波所具有的巨大带宽优势,传输介质所具有的重量轻、低损耗,以及光载波能够抵抗空间存在的各种电磁干扰等,而这也正是目前的电子技术面临的困境。积极研究、探索用光子学技术和方法来进行微波信号的产生、传输和处理等,就成为了微波光子学的热门研究方向。论述了微波光子技术在信号滤波处理等方面的应用以及近年来的研究进展,简要介绍了正系数、负系数、复系数以及单通道微波光子滤波器的基本架构、工作原理及其在卫星通信信号处理中的应用及发展趋势。在有巨大应用前景的单通道微波光子滤波器中,目前已能实现0~20 GHz的频率调谐范围、350 MHz的通道带宽。
Microwave photonics mainly discusses the interaction between microwave and lightwave,which has been used in wire-less access networks,sensing networks,radar,satellite communications,instruments and modern electronic warfare.The advantages of mi-crowave photonics include the huge bandwidth carried by the carrier,light weight,low loss and the immunity to electromagnetic interfer-ence,and these help to overcome the bottlenecks that the traditional electronic technologies have met.Therefore,it is better to explore the photonic techniques to generate,transfer and process the microwave signal.In this paper,a summary of the applications and development of microwave photonics in signal filtering is presented,followed by a simple description of the principles and structures of microwave photonic filters with positive coefficients,negative coefficients and complex coefficients.As to the microwave photonic filter with a single-bandpass,a frequency tuning range of 0~20GHz and a bandwidth of 350MHz have been achieved,which has a prospect in satellite com-munications and radar.