Capacitors are widely used in electronic systems and have a key function in EMC (electromagnetic compatibility) compliance. However, the ageing of capacitors results in an alteration of their parameters, which could pose a threat on the normal operation of systems as well as their EMC compliance. Normally, accelerated ageing is employed to shorten the experiment time. After the ageing, the capacitance and equivalent series resistance (ESR) are measured to evaluate the ageing process. In this paper, a new continuous characterization measurement set-up is implemented in which the accelerated ageing of the capacitors under test (CUTs) is continuously monitored during the overall accelerated ageing process. It significantly improves the continuity of the measurement and eliminates the errors attributed to the interrupting of the ageing process. This method is validated by comparing measurement results from the new measurement method with results of the conventional method. This was done by subjecting two types of film capacitors to thermal and electrical stress in order to evaluate the accelerated ageing effects. Furthermore, a conditional deep neural network with dropout technique is proposed to predict the accelerated ageing conditions of the capacitors. Instead of only forecasting the failure threshold, the proposed network is able to dynamically predict the accelerated ageing conditions at different elevated temperatures and voltages. This leads to a serious reduction of the total measurement time: from 1000h to 200h.

Bluetooth Low Energy (BLE) is a popular wireless communication protocol heavily used in Internet of Things applications. Nowadays, robustness is considered a key requirement in wireless communication. However, radio interference from various sources may affect the performance of BLE devices, leading to channel congestion. Therefore, there is a broadly recognized need of methodologies capable of sensing and avoiding interference. In this paper, two improvements at the data link layer for interference detection and channel selection are proposed to enhance the BLE connection robustness. This paper also presents a wide range of experimental evaluations aiming at validating the improvements and providing insights on both these improvements. Particularly, the communication performance of the BLE link layer is assessed in terms of channel usage distribution, supervision timeout ratio (STR) and packet loss rate (PLR) under different interference environments. Results from these experiments (reliability over 97% and 99% under two different harsh environments) highlight the effects of both improvements on the BLE robustness. Meanwhile, the authority of scheduling the whole mechanism is given to the link layer and even the higher application layer. This paper provides a set of solutions for BLE confronting interference in link layer.

Time-domain near-field scanning is gaining more and more interest within EMC engineering to analyze electromagnetic near-fields of, e.g., quasi-stationar devices. When using a digital oscilloscope to scan the near-fields of an electronic device, the oscilloscope measures time-domain signals that comprise in most cases a large number of frequency components. For many of these components, noncoherent sampling occurs, resulting in spectral leakage when calculating the frequency spectrum of the time-domain signals with the discrete Fourier transform. This paper proposes an improved method to detect the presence of such noncoherently sampled signals as well as an iterative algorithm to obtain accurate approximations of all the frequency components with their accompanying amplitudes and phase angles. The algorithm excels over existing algorithms in obtaining these values especially in situations where several sinusoidal components are close to each other in the spectrum. This is achieved, thanks to an iterative process of removing the influence of the multiple sinusoidal components on each other. This paper contains the mathematical description of the algorithm and a numerical example evaluating the accuracy of the algorithm. The algorithm has a higher accuracy than the existing approaches, e.g., multipoint Interpolated Discrete Fourier Transform (IpDFTs), with only a slight increase of the computational cost.

In this paper, a novel algorithm that selects optimal paths for conducting automated near-field (NF) measurements is presented. The resulting dataset of measurements can then be used to model the complete NF electromagnetic emissions of an electronic device or predict the far-field emissions. The models obtained using the training sets generated with the aid of the proposed algorithm are substantially more accurate compared to existing point-based methods. The algorithm is validated by comparing it against an earlier adaptive sampling algorithm that optimizes point-based measurement datasets.

This paper compares the shielding performance or shielding effectiveness of gaskets for on-board applications when determined with either a stripline method or a reverberation room method. The shielding performance is considered in the frequency range from 1 up to 40 Ghz. Similar to PCB-level enclosures, gaskets for on-board applications differ significantly from other shielding products, therefore requiring an appropriate definition for their shielding effectiveness. It is shown by full-wave simulations that a 3rd order polynomial fit of the shielding effectiveness obtained with the stripline method correlates well with the shielding effectiveness obtained with a reverberation room method, in which case the shielding effectiveness is defined as the ratio between the radiated/received power with and without gasket.

In this paper, the impact of the number of devices on the communication interference in Bluetooth Low Energy (BLE) is studied. The reliability of BLE communication in real life is partially revealed, by investigating the channel hopping features inside. The reliability drawbacks inside BLE are raised and they serve as the basis for future improvement. The reliability is analyzed in terms of the time of the first collision and total collision probability. The result shows that both channel selection algorithms (CSAs) from BLE are not able to deal with interference effectively.