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 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 suggesting the usage of such a technology for real time monitoring applications in environments, like swimming pools, rivers or fish farms.

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 through a vector network analyzer. A relationship between the resonance frequency and the sample permittivity has been found that is well approximated through a 2-parameter exponential. Finally, the model has been validated measuring the dielectric constant of a liquid by the Keysight High temperature probe kit.

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 surface resistance.

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 case of the PA cascaded with a linear network, under load mismatch conditions as imposed by a narrowband passive tuner.