One of the key areas of the LSI group is the design of digital architectures to calculate the fast Fourier transform (FFT). Our goal is to derive highly efficient arquitectures that meet the requirements of the signal processing applications where the FFT is used. This includes architectures for 6G with low-power, low-latency and capable of processing non-power-of-two size; long, high-throughput and low-power FFTs for radio astronomy and space; multidimensional FFTs for radar applications; and efficient FFTs to calculate convolutions in neural networks.