時間至數位轉換器為時間量測系統中相當重要的部分，在各式時間至數位轉換器中，以游標卡尺法能提供較高的量測解析度最具未來性。然而，傳統以游標卡尺法做為基礎的時間至數位轉換器，其使用之振盪器通常需經繁雜的校準程序，因此使用上相當麻煩。有鑑於此，本論文提出一新型軟注入鎖定環形振盪器做為時間至數位轉換器的時脈來源，當振盪器在觸發訊號出現時能快速起振且穩定在預期頻率下。此外，本論文時間至數位轉換器主要應用於室內RFID定位系統，目前於RFID定位技術中最常使用訊號功率強弱來估算物品距離的遠近，但若系統中能有估測訊號傳遞時間的時間至數位轉換器，並藉由兩種方式的相輔相成，則可使室內RFID定位更加準確。
本論文的研究重點在於游標卡尺法時間至數位轉換器的晶片開發及其在RFID系統中距離量測上的應用。利用TSMC 0.18 μm CMOS製程驗證本論文時間至數位轉換器的電路架構。由實驗結果顯示，時間至數位轉換器的量測解析度可小於±1 LSB，符合系統規劃距離誤差落於±30 cm內之預定值。

A time-to-digital converter (TDC) plays an important role in time interval measurement. Among various TDC structures, the vernier-based TDC is promising because it can possess highly accurate time resolution. However, the oscillators used in the conventional vernier-based TDC require complicated calibration procedure. This makes the TDC difficult in use. In this thesis, we purpose a new soft-injection-locked ring oscillator as the clock source for the vernier-based TDC. The proposed oscillator can oscillate immediately and accurately right after the trigger signal arrives. The proposed TDC will be applied in an RFID indoor localization system to measure the time of arrival in the future.
The TDC structure that we proposed was verified by TSMC 0.18 μm CMOS process. Experimental results show that the equivalent resolution is less than ±1 LSB.

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