A Micro-Watt Spectrum-Aware 24 GHz Wake-Up Transceiver and Calibration-Free Thermal-Diffusion Temperature Sensing for IoT Systems 5 views

The growing demand for long-lifetime Internet of Things (IoT) and Artificial Intelligence of Things (AIoT) systems calls for sensing and communication architectures that operate under strict energy constraints with minimal maintenance. In many event-driven applications, sensor nodes remain in low-power standby and activate only upon meaningful stimuli. This dissertation presents two key building blocks for such systems: a calibration-free thermal-diffusion-based temperature sensor and a low-power 24 GHz wake-up transceiver (WuTRx). First, a CMOS electrothermal filter (ETF) temperature sensor is designed and experimentally validated. It achieves calibration-free operation without trimming, with sub-0.01 °C resolution and ±0.8 °C accuracy above 0 °C at 3.5 mW power consumption (1.2 V supply). Practical trade-offs among averaging, latency, and low-temperature performance are also characterized. Second, a 24 GHz wake-up receiver (WuRx) using a channel-embedded OOK (CE-OOK) scheme is proposed for energy-efficient wireless activation. The design achieves 15.7 μW average power consumption, with a tunable latency–power trade-off (14.6 μA at 14 s to 128.5 μA at 1 s). It demonstrates −69.5 dBm sensitivity with <0.1% miss detection under controlled false positive rates. This work represents the first environmentally-aware, multichannel wake-up receiver architecture for AIoT applications, with measured trade-offs among gain, noise figure, sensitivity, and power. Together, these results demonstrate that calibration-free sensing and millimeter-wave wake-up communication are viable approaches for low-maintenance, long-lifetime IoT systems, providing practical design insights for future energy-constrained platforms.

PHD (Doctor of Philosophy)

Wake-Up Receiver (WuRx), 24 GHz Transceiver, Ultra-Low Power, Thermal Diffusivity, Calibration-Free Temperature Sensor, Channel-Embedded OOK (CE-OOK), Spectrum-Aware Communication, AIoT

English

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2026-04-13