A carrier-frequency-independent BPSK demodulator with 100% data-rate-to-carrier-frequency ratio

A novel noncoherent BPSK demodulator is presented for wirelessly-powered biomedical implants. The received data are detected based on rising or falling edge of the digitized carrier, while all components of the circuit are independent of the carrier frequency. Besides simplicity and ultra low-power consumption, the proposed demodulator benefits from an outstanding data-rate-to-carrier-frequency ratio of 100%. Thus, it can easily achieve high data rates with lower carrier frequencies, which is desirable in implantable biomedical applications such as visual prostheses. The circuit is designed and simulated in a 0.18-μm standard CMOS technology and merely consumes 119-μW@1.8 V at a data rate of 10 Mbps. The proposed idea is also supported by experimental results of a proof-of-concept prototype.