A uniform array with the near distance of sensors ensures FI beam pattern at high frequency but is worse at WNG index, while a uniform array with far distance of sensors ensures FI beam pattern at low frequency and is good at WNG index. In case of a wide range of frequencies, the uniform array needs to be rather dense and large in size to cover both near distance of sensors and far distance of sensors, therefore the number of sensors needs to be huge. Thus, a sparse array is an optimal solution because it reduces the number of sensors, ensures the FI beam pattern and increase WNG. Our design method for sparse arrays uses the information from uniform array to seek sensor locations, which is efficient not only in performance but also in computation time.