微波光子滤波器(MPF)是在光域内实现对微波/射频(RF)信号进行滤波的器件。由于微波光子滤波器在射频系统中具有带宽大、快速可调谐、可重构、无电磁干扰(EMI)、低损耗和重量轻等优点，因而这一类器件已经引起了越来越多的人们的兴趣。在概述微波光子滤波器基本原理基础上，分别介绍了现阶段对微波光子滤波器可调谐性、负抽头等问题基本方法的实现，并简要比较了不同方法的优缺点。最后展望了微波光子滤波技术的发展方向和技术难点。

Microwave photonic filter (MPF) can filter microwave and radio frequency (RF) signals directly in optical domain. Because of the advantages such as wide bandwidth, fast tunability, immunity to electromagnetic interference (EMI), low loss and light weight and so on, microwave photonic filters have attracted much attension. After a brief summarization on the basic principle of microwave photonic filter, we several methods used to obtain the tunability, negative tap, etc, for the microwave photonic filter are introduced. Also the advantages and disadvantages of these methods are listed. Finally, the prospects and the difficulties of the technique are discussed.