近十幾年，督普勒雷達用於姿態、跌倒以及生理訊號等非接觸偵測之研究蓬勃發展，特別是在發生新冠肺炎大流行之後，非接觸生理訊號之偵測，更是收到莫大的關注。其無論是在硬體架構的創新，或是在訊號處理上皆結合了各種不同的技術，使其性能更為強大。其中，最為特別的架構便是自我注入鎖定雷達。它受益於其高靈敏度以及架構簡單而獲得愈來愈多的注意。因此，本研究是基於前人在自我注入鎖定雷達的研究理論上，將其以階段性地結合測距和相位陣列等雷達技術，逐步地開發出可同時構建多人三維影像與監測多人生理訊號之雷達系統。
　　第一階段是將具有距離解析度特性的測距技術，如：超寬頻、步階頻率連續波以及頻率調變連續波等技術，達到利用距離解析度來分辨位於不同距離下待測者的生理訊號和減少來自環境的雜波干擾。此外，考慮到以上測距技術需要掃描更大的頻寬以求更好的距離解析度，外差式自我注入鎖定雷達便油然而生，它具有一升降頻射頻前端和一中頻自我注入鎖定電路，並結合步階頻率連續波技術來區分位於不同距離受測者之生理訊號。在第二階段，為了達到更廣的偵測範圍，將外差式自我注入鎖定雷達結合頻率調變連續波與單發射多接收的相位陣列技術，並使用數位波束形成演算法，使其同時具有距離解析度與水平角度解析度等二維空間資訊，使雷達具有二維定位能力，並利用二維的解析度，達到可同時偵測更多人的生理訊號。第三階段則結合多發射多接收的相位陣列，使雷達具有距離解析度、水平角度解析度、以及垂直角度解析度等三維空間資訊，進一步使雷達具有三維成像能力，可辨識待測者的姿勢與方向，並利用其胸腔區域的影像熱點提取更為準確的生理訊號

　　Over the past few decades, Doppler radar research for non-contact detection of posture, falls, and vital signs has flourished. In particular, wireless vital signs monitoring has gained significant attention since the outbreak of the COVID-19 pandemic. Thanks to advancements in hardware architecture and signal processing combined with various technologies, Doppler radar has become a powerful tool. The self-injection-locked (SIL) radar architecture is a unique and special structure that has been gaining more attention and popularity due to its high sensitivity and simple design. Based on the theoretical foundation of SIL radar, this study has combined SIL radar with ranging and phased array technologies to develop a radar system that can simultaneously create 3D images of multiple subjects and monitor their vital signs.
　　In the initial phase, radar systems that employ ranging technologies such as ultra-wideband (UWB), stepped-frequency continuous-wave (SFCW), and frequency-modulated continuous-wave (FMCW) were used to distinguish between subjects’ vital signs at varying distances while reducing interference from clutter. However, obtaining better range resolution necessitates more sweeping bandwidth, which can be challenging. To address this problem, a heterodyne self-injection-locked (HSIL) radar was proposed. It consists of an up- and down-conversion front-end and an intermediate frequency (IF) SIL circuit, and incorporated SFCW technology to differentiate vital signs between subjects at various distances from the radar. In the second phase, a single-input multiple-output (SIMO) phased array with digital beamforming and FMCW technologies was introduced to the HSIL radar. This enabled the HSIL radar to widen its detectable range and provide 2-D spatial positioning (range and azimuth) for multiple subjects, as well as monitor their vital signs. In the final phase, the HSIL radar was upgraded with a multiple-input multiple-output (MIMO) phased array. This enabled it to generate multiple 3-D images of subjects, identify their postures and orientations, and extract more accurate vital signs data from their chest area using image hotspots.

論文審定書 i
摘要 iv
Abstract v
List of Figures viii
List of Tables xiii
Chapter 1 Introduction 1
1.1 Research Motivation 1
1.2 Doppler Radars for Vital Sign Monitoring 3
1.2.1 Continuous Wave Doppler Radar 3
1.2.2 Doppler Radars With Range Resolution 4
1.2.3 Doppler Radars With Angular Resolution 9
1.2.4 Doppler Radars With Image Resolution 11
1.3 Self-Injection-Locked Doppler Radar 14
1.4 Dissertation Overview 16
Chapter 2 1-D HSIL Doppler Radar 18
2.1 Radar System Architecture and Mechanism 18
2.1.1 Radar Architecture 18
2.1.2 Operating Principle 21
2.2 Experimental Setup for Evaluating Radar Performance 26
2.2.1 Experimental Result of Detecting a Single Metal Plate 26
2.2.2 Range Resolution Experiment of Detecting Two Metal Plates 28
2.2.3 Range Resolution Experiment of Detecting Two Subjects 30
2.3 Ranging and Vital Sign Monitoring of Multiple People 32
2.4 Summary 34
Chapter 3 2-D HSIL Doppler Radar 35
3.1 Radar System Architecture and Mechanism 35
3.1.1 Radar Architecture 35
3.1.2 Operating Principle 40
3.2 Experimental Setup for Evaluating Radar Performance 43
3.2.1 Experimental Result of Detecting a Single Metal Plate 43
3.2.2 Resolution Experiment of Detecting Two Metal Plates 47
3.2.3 Resolution Experiment of Detecting Two Subjects 50
3.3 Positioning and Vital Sign Monitoring of Multiple People 52
3.4 Summary 57
Chapter 4 3-D HSIL Doppler Radar 58
4.1 Radar System Architecture and Implementation 58
4.1.1 Switched Antenna Array 60
4.1.2 RF Front-End and IF Stage 62
4.1.3 Controller and DSP 63
4.2 Specifications and Operating Principles 65
4.3 Performance Evaluation Experiments 68
4.3.1 Experimental Result of Detecting a Single Metal Plate 68
4.3.2 Resolution Experiment of Detecting Two Metal Plates 71
4.4 Monitoring Vital Signs of Human Subjects 73
4.5 Summary 77
Chapter 5 Conclusions 78
5.1 Future Work 79
Bibliography 81
Vita 94

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