A 1.55mW mixed-signal integrating mixer for direct spectrum estimation in 0.13μm CMOS

A low power integrating mixer prototype chip for direct spectrum estimation is fabricated for opportunistic spectrum access, interference detection and built-in test applications. The integrating mixer consists of a folded architecture that combines mixing, current-domain windowing, and integration to implement the short-time Fourier transform (STFT). The design operates over a frequency range of 0.05-3GHz, consumes 1.55mW from a 1.2V supply and obtains a dynamic range (DR) of 24dB.