9762 papers found
The aim of this paper is the experimental validation of a Double D coil simplified mathematical model for both static and dynamic inductive power transfer applications. The model is based on the principle of superposition to valuate parameters such as the auto-inductance of an IPT antenna by considering the coil as a finite number of elements. Then, experimental measurements are carried out to validate the model.
The aim of this paper is to propose the architecture of a self-powered sensor node, to be deployed on means of transport to pervasively collect measurements of Particulate Matter (PM) concentration in urban areas. The sensor node is based on the use of low cost PM sensors and exploits LoRaWAN connectivity to remotely transfer the collected data. It is also provided with GPS localization features that allow to associate the measured values with the geographical coordinates of the sampling site. The system is also provided with an innovative, small-scale, solar-based powering solution that...
The aim of this paper is to discuss the usability of Long Range (LoRa) communication technology for the transmission of data collected under fresh water to a Gateway positioned outside water. The technical feasibility of the LoRa transmission channel is discussed from a theoretical point of view, focusing on the definition of the link budget for the proposed scenario. The operation of a prototypal LoRa sensor node is then tested in a real scenario, analyzing the performances according to the different Spreading Factors (SF). Actual data transmission is achieved at a depth of 30 cm, thus...
Non-Intrusive Load Monitoring (NILM) allows providing appliance-level electricity consumption information and decomposing the overall power consumption by using simple hardware (one sensor) with a suitable software. This paper presents a NILM-based monitoring system suitable for a typical house. The proposed solution is a hybrid event-detection approach including an event-detection algorithm for devices with a finite number of states and an auxiliary algorithm for appliances characterized by complex patterns. First results show that the proposed approach works well in detecting and...
A microwave planar sensor based on a split ring resonator is proposed in order to measure the complex dielectric permittivity of material samples. The geometry of the sensor has been simulated and optimized by a commercial electromagnetic software. Simulations in the presence of the dielectric material sample show that the resonance frequency and quality factor are influenced by the material in contact with the sensor itself. A linear relation is obtained between sample loss tangent and the reciprocal of SRR quality factor. Measurements using high-purity grades liquids have been conducted...
This paper is about the design and the realization of a one-port microwave microstrip resonator working in the frequency range from 3 GHz to 6 GHz and its metrological evaluation in order to be employed as a gas sensor. The prototype can be tailored towards a gas target by depositing an appropriate sensing layer of a nanostructured material. The sensor device is achieved by depositing the sensing material as film layer just on the gap of the resonator. Here, the analysis is focused on an Ag@α-Fe 2 O 3 nanocomposite-based microstrip resonator used for sensing the relative humidity that is...
In high frequency applications of superconductors, a relevant parameter used to synthetically describe their performances in terms of surface resistance (proportional to power losses) dependence on the operating frequency is the so-called pinning frequency νp. Customarily, high sensitivity resonant techniques, intrinsically operating at discrete frequencies, are used to estimate νp. By exploiting a dual frequency resonator, we show here that the inaccurate evaluation of νp in the common approach based on single-frequency measurements leads to heavy underestimations of the superconductor...
The surface resistance of the internal coating of pipes is an important characteristic which could indicate zones with the corrosion or leakages. In the particular case of particle accelerators, this parameter becomes even more important for the performance. We designed a scanning cell for the monitoring of the surface resistance along the whole pipe length. We show an example of the geometry optimization of the scanning cell for the octagonal shaped beam screen. Taking into account a TE011 operating mode we determine the geometry of the cell from the point of view of sensitivity and the...
In the context of modern communications systems operating at radio-frequency (RF), the error vector magnitude (EVM) is the most commonly adopted metric to quantify modulation distortion caused by a nonlinear device. While EVM is typically measured with instrumentation featuring broad acquisition bandwidth (BW), here we implement a method based on multiple narrowband vector network analyzer (VNA) acquisitions, allowing for improved measurement accuracy and for broader characterization BWs. We report the EVM characterization of a nonlinear RF power amplifier (PA), analyzing, in particular, the...
A The progressive deployment of Low Power Instrument Transformers in power network for measurement purposes requires studies on their characterization and on the effect of different quantities on their accuracy. In this paper, a fast calibration procedure is introduced. By using a sinc signal, a Low Power Voltage Transformer has been characterized in the power quality frequency range (50 Hz to 2.5 kHz) under the rated voltage conditions.