Monitoring the displacement of tailings dam landslides is a pressing technical challenge in the mining industry. Traditional monitoring solutions relying on integrated air-ground-space surveillance and multi-sensor data fusion have prominent shortcomings, including high costs and excessive energy consumption. To tackle this problem, this paper presents a self-powered ultra-wideband (UWB) landslide displacement monitoring system for tailings dams, which integrates solar energy and radio frequency (RF) energy in a coordinated manner. The system is composed of fixed base stations and mobile tags: the fixed base stations are powered by solar panels and are capable of transmitting RF energy, sending and receiving ultra-wideband positioning signals, and calculating positioning data; the mobile tags are designed as passive devices that can receive RF energy and send and receive positioning signals to transmit surface displacement information of the dam body. Experimental results demonstrate that the system can effectively transmit surface displacement data of the dam body, verifying the feasibility of the technology. By innovatively adopting a passive tag design and a solar-powered supply scheme, the system completely eliminates reliance on external power sources. This research provides an economical and efficient new technical solution for tailings dam safety monitoring.

Currently, the automatic management of roadside parking space remains a significant challenge. Installing cameras next to each roadside parking space is an extremely expensive solution. Utilizing Bluetooth beacons to identify vehicles requires the installation of a Bluetooth device on each vehicle. This not only necessitates vehicle power supply but also poses installation difficulties. Additionally, the Bluetooth devices installed on parking space need to operate for extended periods, consuming a significant amount of electrical energy and requiring grid power supply. To reduce system costs, alleviate installation difficulties, and achieve complete autonomy in power supply, this article proposes a solar-powered and radio frequency (RF) energy transmission-based Internet of Things (IoT) management system for roadside parking space. We have designed both the mobile and fixed terminal of the system. The fixed terminal is powered by solar panels, enabling it to emit RF energy, retrieve vehicle information, automatically track time, and upload data. The mobile terminal is designed as a passive device capable of receiving RF energy and transmitting vehicle information. Through experimental testing, the system successfully achieves automatic retrieval and upload of vehicle information and parking duration, thereby validating the feasibility of the proposed system. Since the mobile terminal is a passive device and the fixed terminal is powered by solar panels, no external power supply is required. This project introduces for the first time the utilization of solar energy conversion into RF power supply, enabling the mobile terminal to function as a passive device without the need for external power or internal batteries.

This work proposes a three-step multi-resolution time-to-digital converter (TDC) architecture based on the vernier delay line (VDL). The proposed architecture uses a delay-locked loop (DLL) to control TDC with a smooth coarse-to-fine strategy. In addition, the fine TDC uses a combination of multiple resolutions to reduce the number of delay cells and flip-flops. This architecture helps to reduce the area and power consumption and maintains high resolution. We proposed architecture performs better trade-offs between power consumption, linearity, accuracy, and measurement range. The simulation results show that the 7-bit TDC based on VDL designed in 180 nm CMOS achieves 5 ps of time resolution, 0.76/-0.8 LSB DNL and 1.02/-1.39 LSB INL at 100 MHz clock frequency while consuming 3.1 mW, which corresponds to the figure of merit (FoM) of 0.242 pJ/Conv.

In this paper, a mutually synergistic hybrid energy harvesting (SHEH) circuit with both AC and DC energy harvesting capability is proposed. Within the proposed hybrid harvester, the vibration period of the piezoelectric transducer (PZT) is served as the switching signal for photovoltaic (PV) energy harvesting so that a dedicated clock generator is saved. Meanwhile, during the sampling phase, a small portion of the PV energy is injected into the PZT as an investment, which enhances the damping force and charge extraction of the PZT. Theoretically, the total synergistically extracted power from the proposed hybrid harvester is more than the sum of the power obtained from each transducer independently. The proposed SHEH circuit is fabricated with a 0.18-$\mu \text{m}$CMOS process. The buck-boost converter with zero-current switching control achieves a peak efficiency of 82.8%, and the maximum efficiency of piezoelectric energy harvesting can reach 4.5 times that of the full-bridge rectifier.

Using coaxial through-silicon technologies, a new 3-D capacitor integrated on a silicon interposer is proposed. The capacitance of coaxial through silicon via (CTSV) capacitors is extracted, analyzed, and compared. The results obtained from the analytical model and the finite-element method exhibit good agreement with various design parameters, and the error between the proposed model and measurement remains less than 7.41%. Due to high capacitance density up to 22.4 nF/mm2, the 3-D capacitor is adopted as a decoupling capacitor for the on-chip low-dropout (LDO) regulator design. The proposed LDO is developed in a 180-nm CMOS technology and shows unique advantages regarding the power supply rejection (PSR) performance, quiescent current, and area compared with that of the conventional LDOs with off-chip capacitors and capacitor-less (CL) LDOs.