(An) ultra-low-power 4-FSK receiver using auto-calibrated Q-enhancement and injection-locking-based demodulation

Abstract

This paper proposes a receiver system that consumes very low power with high data rate for a wireless communication system for cochlear implants. The most important design problem of such a biomedical receiver structure is power consumption due to a limited energy source. Power consumption can be reduced to some extent by using Q-enhancement technology. However, in order to obtain high quality factor, an external inductor must be used, and an automatic calibration method is implemented to compensate for variations due to inductor tolerance, parasitic capacitors, and process variations. In addition, four array frequency shift keying (4-FSK) signals are amplified through a high-Q amplifier, and converted amplitude modulated signals. Also, by using an injection locking oscillator, 4-FSK signals are converted into phase modulated signals. This frequency to amplitude and phase conversion method can distinguish 4-FSK signals, achieving high data rate with ultra-low power.