應用於物聯網之低功率甦醒接收機及頻率鍵移解調器

Abstract

為了使科技更貼近日常生活, 物聯網已是當下不可或缺的重要概念, 其相關的核心技術, 例如：無線感測網路(WSN)搜集各種外界資訊, 同時高效利用有限能量, 在低功率消耗之下, 將擷取資料彙整到後端處理。有鑑於此, 無線收發機將會是發展物聯網周邊應用的關鍵。 促使無線接收機可使用的電氣壽命獲得延長, 必須滿足極低功率的需求, 本論文於無線接收機上提出了兩個解決方案, 首先是一個頻率對時間的頻率鍵移調變(FSK)類比解調器與校正電路, 其二為一個基於能量偵測之低功率甦醒接收機。前者主要以提出一個新穎的類比式解調原理, 不需要付出太多功耗, 即可還原資料; 後者則是以開關鍵移調變(OOK)為接收系統的調變方式, 並以簡約的應用電路, 透過直接包絡偵測之解調行為, 實現資料接收。 本兩設計皆使用台積電90納米製程，頻段為400-457 MHz MedRadio通訊傳輸頻帶。解調器以0.6伏供應電壓實現電路。所處理的中頻信號為4 MHz，頻偏為1 MHz, 所處理的資料速率為1 Mbps, 總系統功耗為17.6 uW，最小可解調的訊雜比為19 dB, 在固定頻偏之下, 藉由校正電路調整, 使中頻信號可適應的範圍為2 MHz。 甦醒接收機以0.5伏供應電壓實現電路, 最大等效資料傳輸量為250 kbps，系統功耗為 1.79 uW, 接收機對曼徹斯特編碼下的靈敏度為-40 dBm。

Wireless transceiver is a key building block for IoT application. In order to realize a low-power tranceiver, this thesis proposes two solutions in receiver. First, a frequency-to-time FSK analog demodulator provides a novel demodulation principle. It’s able to recover the data without excessive power consumption. Second, a low-power wake-up receiver based on energy detection achieves the moderate sensitivity with ultra-low-power operation. The system architecture is simplified because of the OOK modulation. Moreover, the superior performance of power-saving for receiving data is completed by the direct envelope detection method. Both works are fabricated in TSMC 90-nm CMOS technology. And those are operated at 400-457 MHz MedRadio band. For the demodulator, the supply voltage is 0.6 V. The intermediate frequency (IF), frequency deviation, and data rate are 4 MHz, 1 MHz, and 1 Mbps. The total power consumption is 17.6 uW. The detectable signal-to-noise ratio (SNR) is 19 dB. Under the proposed frequency deviation, the range of IF signal can be enhanced into 2 MHz. For the wake-up receiver, the supply voltage is 0.5 V. The maximum effective data rate is 250 kbps. The total power consumption is 1.79 uW. When the carrier is encoded by Manchester coding after the pseudorandom binary sequence in 9, the sensitivity of receiver is -40 dBm.