We propose an add-drop multiplexer (ADM), designed using a purely phase-sampled superstructure fiber Bragg grating and capable of compensating accumulated link dispersion over a wide bandwidth. Both the grating period and the sampling period are chirped linearly along the length of grating for realizing broad-band compensation. We also discuss how such gratings can be used to design a multichannel ADMs and channel interleavers while compensating the dispersion for all reflected channels.