| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 107 === In this thesis, a novel measurement method is proposed to characterize transmission-type and reflection-type injection-locking oscillators (ILO), which are the kernel components of the self-injection-locked (SIL) radars. According to the results, the transmission-type ILO has a better sensitivity than that of reflection-type one. As the transmission-type ILO is integrated with a commercial phase-locked loop (PLL) chip, it can build up a phase- and self-injection-locked (PSIL) vital-sign radar sensor. Here, the PLL not only stabilizes the transmitting radio-frequency source, but also plays the role of the vital-sign demodulator. Two high-sensitivity and non-contact PSIL radars, which are with and without a low-noise amplifier in the receiving path, are developed in this thesis. Then, both two radars are evaluated by the metallic-plate variation and human chest physiological movement. The demodulated vital-sign signals will be converted into digital signals by the microcontroller module and sent into the computer for performing digital signal processing (DSP). Based on the measurement comparisons of the two radars, this thesis gives some further optimization strategies. The developed radars have the advantages of small circuit size, low fabrication cost, and high-sensitivity. In addition, since the microcontroller module, which is adopted in this thesis, supports wireless communication interfaces, such as Bluetooth and WIFI, the vital signs can be sent to the cloud for internet of thing (IoT) applications.
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