適用於植入式醫療通訊頻段之低功率無線接收機

Abstract

近年來，國人對於健康生理的監控愈來愈多的需求下，使得植入式醫療通訊系統得以快速地發展。因此在這樣的需求背景下，本論文將針對植入式醫療通訊系統提出兩種不同的調變機制的接收機 ─ “開關鍵結調變接收機”及 “頻率移位鍵結調變接收機”。 本篇論文所提出的開關鍵結調變接收機實作在TSMC CMOS Standard 0.18um製程下，而接收機包含以下的電路區塊 ─ 低電壓放大器、多級增益放大器、雙極差動包絡檢波器以及後級的比較器，其中本篇論文所提出的雙極差動包絡檢波器更是此接收機的創新想法之一，並且改善以往包絡檢波器容易因為受到環境雜訊干擾等因素，進而提高整體接收機的效能表現。此接收機在資料傳輸速率為76.8kbps和0.1%誤碼率時可以達到-68dBm的靈敏度，總功率消耗為0.8mW。 不同於前段所提出的開關鍵結調變接收機，本論文更針對抗噪性更好的頻率移位鍵結調變來進行設計出創新性的接收機架構，其中頻率移位鍵結解調器更是屏棄掉過去傳統的自我混波解調或是延遲相位解調的方式，而是改採用充電泵的特性來辨別不同頻率，此方法將造成不同頻率的訊號有不一樣的充電電壓高度差，因此有別於傳統的解調機制，此解調器將可以省下許多不必要的電能消耗。最後，整體接收機在資料傳輸速率為75kbps和0.1%誤碼率時更可以達到-77dBm的靈敏度，總功率消耗為1mW。

In recent years, the demands of health care systems are growing up rapidly, so the medical implantable communication systems are quickly developed. Therefore, this paper will focus on medical implantable communication system and propose two different mechanisms of receivers ─ 'On-off keying modulation receiver,' and 'frequency-shift key modulation receiver. ' This On-off keying modulation receiver is implemented in TSMC CMOS Standard 0.18um process, and the receiver contains the following circuit blocks ─ a low-voltage amplifiers, a multi-stage gain amplifier, a differential envelope detector and one comparator. This differential envelope detector is an innovation circuits and improves the shortcut of the traditional envelope detector in the past. For example, the noise will interfere the traditional envelope, but the proposed detector can eliminate the common noise to improve overall performance. In summary, this receiver achieves the sensitivity of -68dBm at 0.1% BER with 76.8kbps data rate, and total power consumption is 0.8mW. As we mentioned before, this paper is also proposed a frequency-shift key modulation receiver which is using a charge pump to demodulate the two differential frequency signals, unlike the conventional demodulation systems , the demodulator will be able to save unnecessary power consumption. Finally, this FSK receiver is implanted in TSMC CMOS Standard 0.18um process and achieves the sensitivity of -77dBm at 0.1% BER with 75kbps data rate, and total power consumption is 1mW.