以CMOS 0.18微米製程實現400 MHz植入式醫療通訊系統之數位校正超再生接收機

Abstract

In this work, we adopt the super-regenerative receiver to implement the receiver for the Medical Implant Communications Service (MICS) applications. The receiver is designed to demodulate the on-off keying signal. The architecture is simple and consumes low power. The proposed topology incorporates digital circuits to generate the quench signal on chip. In addition, an open-loop frequency calibration loop is proposed to adjust the digitally-controlled oscillator frequency to the MICS band. Although a phase-locked loop can also lock the oscillator frequency and achieve precise frequency calibration, its locking time is long. This proposed frequency calibration loop can adjust the oscillator frequency in 4 μs; thus, it saves energy consumption. Fabricated in a 0.18-μm CMOS process, the measurement results show the proposed topology dissipates 3.5 mA from a 1.5-V supply. The total calibration time is less than 20 μs. The receiver has a sensitivity of -83 dBm and a maximum data rate of 1 Mbps. The chip area of the fully-integrated super-regenerative receiver is 1.47 mm X 1.46 mm including pads. The core area is 0.9 mm X 1 mm.