A 5GS/s 12.2pJ/conv. analog charge-domain FFT for a software defined radio receiver front-end in 65nm CMOS

This work describes the design of CRAFT (Charge Re-use Analog Fourier Transform): an RF front-end channelizer for software defined radios (SDR) based on a 16 point analog-domain FFT. The design relies on charge re-use to achieve 47dB average SNDR on a 5GS/s I/Q input, and consumes only 12.2pJ/conv. Due to its wide-band and low power channelization capabilities, it is expected to reduce the sample rate and dynamic range requirements for wide-band digitization in SDRs.