Bandpass multitap microwave photonic filter with a round‐trip configuration

We propose a novel bandpass microwave photonic multitap filter configuration using a section of Hi‐Bi fiber in a round‐trip configuration. The configuration makes use of a chirped FBG both as a mirror and a dispersive device. Measured results are presented to show a two‐tap and three‐tap filter response, with a notch rejection greater than 35 dB and tunability of the level of secondary sidelobes by adjusting a polarization controller.