The universal filtered multi-carrier (UFMC) technique has been proposed as a prominent waveform candidate for fifth generation (5G) communication techniques. However, UFMC systems exhibit a high peak-to-average power ratio (PAPR), which causes serious degradation in the performance of the system. Therefore, this paper puts forward an effective hybrid PAPR reduction method to reduce the high PAPR of the UFMC system. The proposed hybrid scheme consists of a combination of precoding and non-linear companding techniques (NLCTs). A comparative analysis of the performance of different precoding methods, NLCTs, and hybrid methods is investigated in terms of the cumulative distribution function of the PAPR and the bit error rate (BER). Simulation results show that the proposed hybrid UFMC system has better PAPR reduction performance compared to conventional NLC and precoded UFMC systems. Moreover, the BER analysis of the UFMC system verifies that the proposed hybrid technique shows better BER performance compared to conventional companding techniques.

The surge in electronic devices and wireless communication technologies has increased the demand for effective electromagnetic interference shielding and microwave-absorbing materials. Traditional electromagnetic interference (EMI) shielding materials, which predominantly utilize metals and polymer composites, pose significant environmental challenges due to their non-biodegradable nature. Recently, a range of novel electromagnetic shielding materials has been developed, with composite materials derived from waste sources emerging as promising alternatives for next-generation shielding solutions. This comprehensive review explores sustainable materials derived from various recycled waste sources for EMI shielding applications. It begins by examining the fundamental principles and mechanisms of EMI shielding and absorption techniques necessary for cost-effective performance. The review further investigates a variety of sustainable materials, including agricultural residues, industrial by-products, animal waste, and electronic waste, evaluating their potential for EMI shielding. Additionally, it explores the structural characteristics, electromagnetic properties, and synthesis methods of composite materials created from different raw material combinations. The review highlights the processing techniques and integration strategies used to develop effective shielding materials, as well as the potential applications of these materials and the challenges associated with their synthesis. The innovative use of solid waste materials from diverse origins in creating these shielding materials not only enhances their efficiency but also contributes to effective waste management and environmental sustainability.

The growing demand for sustainable and energy-efficient construction has driven significant interest in the development of advanced insulation materials that reduce energy usage while minimizing environmental impact. Although conventional insulation materials such as polyurethane, polystyrene, and mineral wools offer excellent thermal and acoustic performance, they are derived from non-renewable sources, have high embodied carbon (EC) (up to 7.3 kg CO₂-eq/kg), and pose end-of-life disposal challenges. Thus, this review critically examines the emergence of insulation materials derived from natural and recycled sources, which align with circular economy principles by minimizing waste, promoting material reuse, and extending product life cycles. Sustainable alternatives such as sheep wool, hemp, flax, and jute not only exhibit competitive thermal conductivity (as low as 0.031–0.046 W/m·K) and very good sound absorption but also offer low EC, biodegradability, and regional availability. Despite some limitations, including variable fire resistance and thickness requirements, these bio-based insulators present a viable path toward greener building solutions. The review highlights that waste-based insulation materials are essential for sustainable construction due to their low EC, renewability, and contribution to waste reduction, making them a necessary alternative even when conventional materials demonstrate superior short-term performance.

Filtered orthogonal frequency division multiplexing (F-OFDM) is one of the most prominent waveform candidates when it comes to fifth-generation (5G) wireless communication and beyond. This paper analyzes the performance of the F-OFDM system in terms of the peak-to-average power ratio (PAPR) and bit error rate (BER). The F-OFDM system exhibits a high PAPR, which introduces earnest deterioration in its performance. Consequently, an efficient PAPR-reduction technique has been recommended to reduce the effect of the high value of PAPR of the F-OFDM system. The prospective two-piecewise companding (TPWC) scheme effectively reduces the peak power by analyzing large and small amplitudes individually, so its outcome has both piecewise linear and continuous characteristics. The performances of different PAPR reduction techniques are compared in terms of PAPR complementary cumulative distribution functions and BERs. It is shown that the proposed TPWC transform can significantly reduce PAPR with reduced computational complexity compared with conventional companding techniques.

In this paper, two different patch antenna geometries are proposed for wireless sensor applications involving electromagnetic propagation from inside the jet engine to our designed relaying antenna at the rim of the inlet. First, an enhanced modified version of our earlier proposed two-element circular patch antenna array is proposed. We follow with a fresh new design based on two-element array of hybrid rectangular circular patch antenna geometry. Both antenna designs are discussed in light of basic governing equations enabling initial design calculations, intuitions behind selecting the design elements based on desired propagation characteristics, simulation results, as well as fabrication and experimental measurements. Because of the environmental constraints, the proposed antennas need to be an extremely low profile and ultrathin. The proposed relaying antennas are designed to have a dual-beam pattern, one of which is directed toward the inside of the jet engine. The antennas are simulated using HFSS as well as fabricated and measured inside an anechoic chamber. Experimental results, which sufficiently agree well with the simulation results, demonstrate the achievement of the desired characteristics by fabricated antennas for deployment on jet engines.

Analyzing electromagnetic propagation inside jet engine turbines is a challenging and important research topic due to its potential applications in both civil and military fields. Electromagnetic modeling of such complex cavities is very difficult due to their complex geometry and the harsh surrounding environment, as well as the rotating metallic parts they contain. In addition, it is extremely difficult to extract the field values from arbitrarily shaped model geometries having large sizes, complex terminations, and cross-section variations.