The Internet of Things (IoT) envisions the interconnection of all electronic devices, ushering in a new technological era. IoT and 5G technology are linked, complementing each other in a manner that significantly enhances their impact. As sensors become increasingly embedded in our daily lives, they transform everyday objects into “smart” devices. This synergy between IoT sensor networks and 5G creates a dynamic ecosystem where the infrastructure provided by 5G’s high-speed, low-latency communication enables IoT devices to function more efficiently and effectively, paving the way for innovative applications and services that enhance our awareness and interactions with the world. Moreover, application-oriented and multifunctional antennas need to be developed to meet these high demands. In this review, a comprehensive analysis of IoT antennas is conducted based on their application characteristics. It is important to note that, to the best of our knowledge, this is the first time that this categorization has been performed in the literature. Indeed, comparing IoT antennas across different applications without considering their specific operational contexts is not practical. This review focuses on four primary operational fields: smart homes, smart cities, and biomedical and implantable devices.

The transition from 5G to 6G wireless systems introduces new challenges at the physical layer, including the need for higher frequency operations, massive MIMO deployment, advanced beamforming techniques, and sustainable energy harvesting mechanisms. A plethora of feature articles, review and white papers, and roadmaps elaborate on the perspectives and research challenges of wireless systems, in general, including both unified physical and cyber space. Hence, this paper presents a comprehensive review of the technological challenges and recent advancements in wireless communication hardware that underpin the development of next-generation networks, particularly 6G. Emphasizing the physical layer, the study explores critical enabling technologies including beamforming, massive MIMO, reconfigurable intelligent surfaces (RIS), millimeter-wave (mmWave) and terahertz (THz) communications, wireless power transfer, and energy harvesting. These technologies are analyzed in terms of their functional roles, implementation challenges, and integration into future wireless infrastructure. Beyond traditional physical layer components, the paper also discusses the role of reconfigurable RF front-ends, innovative antenna architectures, and user-end devices that contribute to the adaptability and efficiency of emerging communication systems. In addition, the inclusion of application-driven paradigms such as digital twins highlights how new use cases are shaping design requirements and pushing the boundaries of hardware capabilities. By linking foundational physical-layer technologies with evolving application demands, this work provides a holistic perspective aimed at guiding future research directions and informing the design of scalable, energy-efficient, and resilient wireless communication platforms for the Future Internet. Specifically, we first try to identify the demands and, in turn, explore existing or emerging technologies that have the potential to meet these needs. Especially, there will be an extended reference about the state-of-the-art antennas for massive MIMO terrestrial and non-terrestrial networks.

A novel miniature all-polarization Γ antenna array for demanding 5G and Internet of Things (IoT) applications is proposed. The antenna is designed to be able to perform Direction of Arrival (DoA) and Beamforming keeping antenna’s footprint as minimal as possible to fit in or wrapped around any IoT device. It is a non-uniform square array comprised of novel right corner dipoles which are mirror placed to additionally allow all polarization property. These properties are inherited from its approximate equivalence to a cross-dipole antenna with additional features and flexibility. An analytical mathematical formulation is presented resulting to a closed form for the Γ-dipole as well as the 4 dipoles array. Numerical simulations proved the antenna performance and verified that all of its features are approximately retained even when it is curved. The antenna is prototyped in both an improvised wire dipole (planar or curved) ad as printed on an FR-4 substrate. The measured results confirmed the analytical and numerical ones regarding the antenna all-polarization, beamforming and direction of arrival features.

The general objective of the work is to propose, examine, and study the innovations needed, providing a roadmap in order to place the next generation of wireless communication vision and concepts into technological reach. The main trends and directions are identified; relative challenges are addressed; and needed solutions are anticipated, proposed, and evaluated. In detail, to address the role of the antenna system in the wireless communication evolution, in the work at hand, we examine the challenges addressed by the increase in the degrees of freedom of the radiator systems. Specifically, we study the increase in the degrees of freedom provided by gMIMO, reconfigurable intelligence surfaces (RIS), holographic metasurfaces, and orbital angular momentum (OAM). Then, we thoroughly examine the impact that those potent technologies deliver to the mmWave, satellite, and THz wireless communications systems.

This work presents a comparative analysis of microwave ablation applicators, including both antenna-based and open waveguide designs, which are guided and inserted into tumors via catheters. Applicators previously proposed in the literature are evaluated through both electromagnetic and thermal simulations. The objective is to assess temperature distribution within the tumor and surrounding healthy tissues; with a focus on identifying patterns of heat diffusion. Although a variety of applicators have been designed, each typically operates at different central frequency or targets specific tumor shapes and tissue types. In this study, we standardize conditions by analyzing multiple applicators’ designs for the same tumor type. The results highlight the shape of the ablation zone and corresponding temperature distribution, offering insights into potential healthy tissue damage. This comparative analysis provides critical information for optimizing microwave ablation applicators for more precise and effective treatment.

The integration of embedded software in multi-sensor wearable devices has revolutionized real-time monitoring across health, fitness, industrial, and environmental applications. This paper presents a comprehensive approach to designing and implementing embedded software architectures that enable efficient, low-power, and high-accuracy data acquisition and processing from heterogeneous sensor arrays. We explore key challenges such as synchronization of sensor data streams, real-time operating system (RTOS) integration, power management strategies, and wireless communication protocols. The reviewed framework supports modular scalability, allowing for seamless incorporation of additional sensors or features without significant system overhead. Future research directions of the embedded software include Hardware-in-the-Loop and real-world validation, on-device machine learning and edge intelligence, adaptive sensor fusion, energy harvesting and power autonomy, enhanced wireless communications and security, standardization and interoperability, as well as user-centered design and personalization. By adopting this focus, we can highlight the potential of the embedded software to support proactive decision-making and user feedback through edge-level intelligence, paving the way for next-generation wearable monitoring systems.