A 32-Gb/s CMOS Receiver With Analog Carrier Recovery and Synchronous QPSK Demodulation

A 40-nm CMOS receiver (RX) capable of performing A-to-D-converter-less carrier recovery including frequency and phase tracking and coherent QPSK demodulation is presented. It operates in frequency-acquisition mode, followed by phase-tracking mode. It is meant as a demodulator of a 270-GHz RX operating at an intermediate frequency of 45 GHz. The highest data-rate of 32 Gbit/s was achieved dissipating 351 mW, amounting to an energy-per-bit of 11 pJ/bit.