This paper presents a set of measurements in order to experimentally study transfer impedance of coaxial cable RG 213. Both the transfer impedance (Zt) and the Shielding Effectiveness (SE) are essential in the considerations of the EMC project. In this context, this work presents a procedure to measure the transfer impedance of two coaxial cables RG 213 under the same conditions and compare the measurements with theoretical references. The results of transfer impedance (Zt) measurements and theoretical references are quantified through the Feature Selective Validation technique.

The interference in adjacent cells and the control of the boundaries have being vastly investigated since the conception of the first cell phone networks. A very large number of small cells are required for new 5G mobile networks, and therefore it is even more important to determine the correct mobile station positioning as well as the control boundaries. In order to minimize these problems, this paper proposes a simple and efficient system that improves the control of the Mobile Management Entity (MME) defined in the Release 8 of 3GPP. The system uses a tracking arrangement capable of determining the direction of the mobile station in the cell area. This information can be used to predict handover between adjacent nodes (changing of cell) minimizing a great problem, the high traffic in the backhaul network. In order to reach these goals, two or more receiver antennas are used as a Radio Direction Finder (RDF) and phase controlled directional antennas or massive multiple-input and multiple-output antennas pointing to different irradiation channels towards different directions. The theoretical section developed in this study was successfully confirmed by the experimental setup with results very closed to the developed formulation.

Cybersecurity in radio frequency (RF) technologies has become a critical concern, driven by the expansion of connected systems in urban and industrial environments. Although research on wireless networks and the Internet of Things (IoT) has advanced, comprehensive studies that provide a global and integrated view of cybersecurity development in this field remain limited. This work presents a scientometric and systematic review of international publications from 2009 to 2025, integrating the PRISMA protocol with semantic screening supported by a Large Language Model to enhance classification accuracy and reproducibility. The analysis identified two interdependent axes: one focusing on signal integrity and authentication in GNSS systems and cellular networks; the other addressing the resilience of IoT networks, both strongly associated with spoofing and jamming, as well as replay, relay, eavesdropping, and man-in-the-middle (MitM) attacks. The results highlight the relevance of RF cybersecurity in securing communication infrastructures and expose gaps in widely adopted technologies such as RFID, NFC, BLE, ZigBee, LoRa, Wi-Fi, and unlicensed ISM bands, as well as in emerging areas like terahertz and 6G. These gaps directly affect the reliability and availability of IoT and wireless communication systems, increasing security risks in large-scale deployments such as smart cities and cyber–physical infrastructures.

Ensuring proper shielding is essential for the electromagnetic compatibility of electronic devices and systems. This article investigates the shielding effectiveness of coaxial cables and connectors using an electric field probe. The study aims to identify shielding failures early to prevent costly fixes later. A method for measuring the electric field radiated by connectors and cables in both near-field and far-field conditions is presented. Additionally, an electromagnetic virtual model of the connector and cable was developed, incorporating the dimensions and properties of the dielectric material. The simulations focused on the impact of different dielectrics on the resonant frequency of the electric field, specifically common-mode energy. The results showed that the dielectric properties do not affect the resonant frequency in the presence of a common-mode current distribution.

This paper presents a circuit capable of reducing the power used to transmit signals from implanted biomedical wireless sensors. Nowadays, Quasi-Digital sensors are an interesting option that satisfies key performances such as low voltage, low power, low cost, good accuracy and small die area [1]. Those sensors send out analog information using digital signals, either by changing their frequency, period or duty-cycle. In all of them, energy is consumed during the transmitter operation. We propose a power savings by reducing the period that the transmitter is turned on. The proposed circuit changes the square signal of a voltage to frequency converter (VFC) into shorter pulses, but keeping the frequency of the original signal. It generates a Pulse Interval Modulation - PIM signal to be transmitted. We implemented the circuit layout in IBM 130nm CMOS technology. Simulation results demonstrated the circuit work as expected, and the savings may reach over 80 percent.

The reuse of industrial residues has gained importance due to environmental and public health concerns associated with improper waste disposal. Steel scale (CDA), a by-product of machining and rolling operations, represents a residue with technological potential for incorporation into polymer composites. This study developed a low-cost and sustainable material by reinforcing an orthophthalic polyester matrix with CDA and systematically evaluated its mechanical, thermal, and structural properties. Four formulations were prepared based on the maximum feasible filler loading: R (pure resin), C1 (50% CDA), C2 (100% CDA), and C3 (150% CDA). Composites were manufactured by cold-press molding under a two-ton compressive load. Characterization included tensile, flexural, and impact testing, thermogravimetric analysis (TGA), thermal conductivity, apparent density, liquid absorption, and morphological assessment by scanning electron microscopy (SEM). CDA incorporation reduced tensile and flexural strength but increased elastic modulus, impact toughness, and thermal conductivity. The C3 composite exhibited the highest thermal stability, retaining more than 50% of its initial mass at 500 °C. Density and liquid absorption increased proportionally with filler loading, and SEM revealed heterogeneous microstructures with particle agglomeration, sedimentation, and interfacial gaps, explaining the mechanical and thermal trends. The findings demonstrate the feasibility of producing dense and low-cost polyester composites reinforced with steel scale. The structure–property relationships identified in this study establish a foundation for subsequent investigations focusing on additional functional behaviors of this waste-derived material system.