It is crucial to extend the electromagnetic compatibility (EMC) studies to the new frequency regions where modern telecommunication systems operate, specifically those related to the fifth-generation (5G) technology standard for broadband cellular networks. Electric autonomous vehicles (EAVs) are systems that feature 5G technology on board and for which it is essential to ensure the proper management of EMC to prevent malfunctions. Given the considerable development of the EAV-related sector, new materials and solutions for EMI shielding with properties that reduce interference in the frequency regions of 5G technology are being investigated. Today, meatal-based solutions are the most common EMI shielding materials used to mitigate EMC problems. Nevertheless, with the appearance of EAVs, it is needed the design of novel materials that provide a significant balance in terms of shielding effectiveness (SE) and mechanical properties. Thereby, carbon nanotubes (CNTs) are an attractive alternative to conventional EMI shielding materials due to their characteristics. The lightweight condition, flexibility, cost-effectiveness, easy processing, and resistance to corrosion made this new type of material perfect to be used in the field of EAVs. This contribution focuses on describing and characterizing three nanocomposite materials manufactured by loading a polymer matrix with 5%, 7%, and 10% CNT concentrations, respectively. The SE measurement is carried out with a coaxial sample holder based on the standard ASTM D4935-18. This measurement setup makes it possible to determine the performance of the three materials under test up to 18 GHz, covering part of the operation frequencies of 5G systems.

The study and measurement of the shielding effectiveness (SE) of planar materials is required to predict the suitability of a certain material to form an enclosed electromagnetic shield. One of the most widely used standards for measuring the SE of planar materials is ASMT D4935-18. It is based on a coaxial sample holder (CSH) that operates up to 1.5 GHz. Due to this standard’s frequency limitations, new variants with higher frequency limits have been developed by decreasing the size of the CSH conductors and the samples. However, this method and its high-frequency variants require two types of samples with very specific geometries and sizes. This method is unsuitable for certain types of nanomaterials due to their complex mechanization at such undersized scales. This contribution proposes an alternative SE measurement method based on an absorber box that mitigates the problems presented by the ASTM D4935-18 standard. The SE of rigid nanomaterial samples based on several concentrations of multi-walled carbon nanotubes (MWCNT) and two different fiber reinforcements have been obtained.

The development of new advanced functionalities, miniaturization, and the aim of obtaining optimized performance in electronic devices significantly impacts their electromagnetic compatibility (EMC). As electronic components become more densely packed on a printed circuit board (PCB), unintended coupling between components can cause electromagnetic interference (EMI). These requirements result in design restrictions that make using a board level shield (BLS) essential in reducing intra-system EMI in PCB designs. This contribution focuses on studying and characterizing a BLS solution based on combining a noise suppression sheet (NSS) with an aluminum layer to reduce intra-system EMI coupling. This hybrid solution has the advantage of providing a shielding option that does not require any electronic redesign. It does not need a footprint or a ground connection as it can be affixed over the EMI source. The solution is expected to provide higher attenuation levels than using only an NSS by combining the absorbing properties of the magnetic material and the loss mechanism of the metal. In order to verify the effectiveness of the hybrid BLS proposed solution, the magnetic near-field emissions of an EMI source are analyzed in this study. The experimental measurements and simulated results demonstrate a significant increase (51.6 dB at 1 GHz) in the shielding effectiveness (SE) provided by the proposed solution compared to a conventional NSS.

Accurate characterization of shielding effectiveness (SE) is essential for evaluating electromagnetic interference shielding materials in high-frequency applications such as 5G communications, automotive, radar, and aerospace. Standardized methods like ASTM D4935-18 and IEEE 299-2006 have frequency limitations, precise sample preparation, and demand complex experimental setups that can hinder practical implementation. This study presents an advanced characterization of an optimized Absorber Box methodology that enhances SE measurement accuracy, extends the frequency range beyond 1.5 GHz, and minimizes edge diffraction effects. The proposed approach provides a controlled testing environment in a more compact setup compared to anechoic chambers, facilitating practical implementation without compromising precision. The system’s reliability is validated through numerical simulations using finite element method analysis. Experimental results confirm the method’s ability to differentiate materials with different SE, demonstrating strong agreement between simulated and measured data. This approach offers a flexible and robust alternative to conventional SE measurement techniques, making it particularly advantageous for high-frequency shielding material characterization.

This paper presents the implementation and continuous refinement of a questionnaire-based assessment approach for laboratory instruction in undergraduate engineering education. In this method, students complete individual questionnaires at the end of each lab session. It was introduced to address challenges associated with traditional evaluation methods such as group reports. Over multiple academic years, the approach was applied in core laboratory subjects within the Degree in Electronic Engineering for Telecommunications at the University of Valencia. Based on student feedback collected through structured surveys, the teaching team introduced key modifications—most notably, the reformulation of test items and the inclusion of performance checkpoints—to improve alignment between assessed outcomes and the learning process. Analysis of student responses before and after these changes indicates improved perceptions regarding fairness, relevance, and overall satisfaction with the assessment method. The results support the effectiveness of this approach in enhancing student engagement and instructional consistency, while highlighting areas for further pedagogical development.