Super-Regenerative Receiver for Biomedical Applications

In recent years, a rapidly aging population is far outstripping our ability to provide services to support it. Using wireless monitoring and recording for real-time physiological parameters from a patient body is necessary. Therefore, a super-regenerative receiver for biomedical applications and a phase-locked loop for improving voltage controlled oscillator are proposed in this thesis. At last, we do analysis on fundamental problems of super-regenerative receiver and put forward methods to solve them. The super-regenerative receiver and phase-locked loops are both implemented and fabricated in UMC standard 0.18 CMOS process. The super-regenerative receiver is to demodulated OOK signals. It operates at 402M-405M Hz and 1.5 Volt. The measured sensitivity is -62dBm with 100K bps data rate, and power consumption is 561.7uW. The phase-locked loop is to improve the performance of voltage controlled oscillator in the super-regenerative receiver. We use a crystal oscillator as reference frequency, and a third-order loop filter. It also operates at 1.5 Volt. Finally, we analyze fundamental problems in super-regenerative receiver. The core circuit, voltage controlled oscillator, is vulnerable to variations brought by temperature and process, and influences the initial value and slope of start-up time. As a result, some errors arise during the demodulation stage. We propose some methods to solve those problems. Besides, we also investigate bit error rate and the optimal signal detection point of the super-regenerative receiver, in order to achieve minimum bit error rate.