A sinusoidal chirp structure is proposed to improve the performance of fibre gratings as dispersion compensators and multichannel filters. Nearly ideal refiection spectra from sinusoidally chirped fibre gratings are exhibited.The bandwidth utilization defined as the ratio of -1 dB to -30 dB bandwidths could be higher than 0.85, even up to 0.985. The sinusoidal chirp can be applied to the sampled fibre gratings to enhance channel uniformity. We demonstrate 141 uniform channels with a 25-GHz spacing for high dense wavelength multiplexing applications.