超高Q微波光子滤波器的研究进展

微波光子滤波器是一种具有射频滤波功能的光学子系统。相对于普通的电域射频滤波器件，微波光子滤波器具有高带宽、低损耗以及不受电磁干扰影响等优点。Q（即品质因数）是衡量带通滤波器性能的主要参数之一，其大小反映了滤波器的频率选择特性。已报道的各种提高微波光子滤波器Q的方法中，基于多级滤波器级联的结构能够显著提高滤波器的Q，因而得到广泛关注。本文以超高Q为主线，综述了基于级联结构的微波光子滤波器的研究进展，并对微波光子滤波器的下一步研究进行了展望。

Research Progress of Ultrahigh Q Microwave Photonic Filters

Microwave photonic filters, which have attracted great research interest in the past few decades, are photonic subsystems carrying out functions of radio frequency (RF) filtering. Their advantages mainly include high bandwidth, low insertion loss, immunity to electromagnetic interference, etc. Quality factor (Q) value, which determines the performance of the frequency selectivity, is one of the most desired features of microwave photonic filters. Among various structures proposed so far to improve Q values of microwave photonic filters, multi-stage filters with cascaded structures have attracted lots of interests, which can increase the Q values greatly. The newly proposed structures on ultrahigh Q IIR microwave photonic filters with architectures of cascaded multi-stage filters are reviewed. Future directions of research in this area are also discussed.