A Highly Accurate Current Mode Analog Implementation of Radix-2 FFT/IFFT Processor

摘要

The discrete Fourier transform is a very powerful tool of digital signal processing used for spectral domain analysis of signals. The radix-2 fast Fourier transform (FFT) is the most popular algorithm for calculation of DFT for its simplicity. Applications where DFT and IDFT operations both are needed should include a single computational block which can calculate both DFT an IDFT as per the need. Analog implementation of DFT has low power consumption and takes less area on silicon. The proposed technique discusses the analog hardware implementation of eight point FFT/IFFT using radix-2 algorithm. This approach saves a lot of area and memory requirements. The FFT hardware is designed using cascode current mirror for higher accuracy. Mode selection between FFT/IFFT is done with switch arrangement. The circuit is tested rigorously with real and complex inputs using SPICE simulation with BSIM4 65nm CMOS process.