A survey of broadband frequency invariant beamformer

In the broadband signal processing, in order to receiving broadband signals without distortion resulting from the different relative aperture, it is valuable to study the Frequency-invariant beam patterns (FIBPs). Based on the array structure, this paper will summarize some new methods to design a broadband beamformer with an FIBP. There will be two categories: One-dimensional arrays and Multidimensional arrays. For one-dimensional array, there are substitutions method, minimax frequency invariant beamforming method, etc. For multi-dimensional array, there are methods based on Bessel function method, and so on. Finally, we will discuss the pros and cons of every method.