Multiple-input multiple-output (MIMO) technology has emerged as a highly promising solution for wireless communication, offering an opportunity to overcome the limitations of traffic capacity in high-speed broadband wireless network access. By utilizing multiple antennas at both the transmitting and receiving ends, the MIMO system enhances the efficiency and performance of wireless communication systems. This manuscript specifies a comprehensive review of MIMO antenna design approaches for fifth generation (5G) and beyond. With an introductory glimpse of cellular generation and the frequency spectrum for 5G, profound key enabling technologies for 5G mobile communication are presented. A detailed analysis of MIMO performance parameters in terms of envelope correlation coefficient (ECC), total active reflection coefficient (TARC), mean effective gain (MEG), and isolation is presented along with the advantages of MIMO technology over conventional SISO systems. MIMO is characterized and the performance is compared based on wideband/ultra-wideband, multiband/reconfigurable, circular polarized wideband/circular polarized ultra-wideband/circular polarized multiband, and reconfigurable categories. The design approaches of MIMO antennas for various 5G bands are discussed. It is subsequently enriched with the detailed studies of wideband (WB)/ultra-wideband (UWB), multiband, and circular polarized MIMO antennas with different design techniques. A good MIMO antenna system should be well decoupled among different ports to enhance its performance, and hence isolation among different ports is a crucial factor in designing high-performance MIMO antennas. A summary of design approaches with improved isolation is presented. The manuscript summarizes the various MIMO antenna design aspects for NR FR-1 (new radio frequency range) and NR FR-2, which will benefit researchers in the field of 5G and forthcoming cellular generations.

This review provides a comprehensive analysis of the design, materials, fabrication techniques, and applications of flexible wearable antennas, with a primary focus on their roles in Wireless Body Area Networks (WBANs) and healthcare technologies. Wearable antennas are increasingly vital for applications that require seamless integration with the human body while maintaining optimal performance under deformation and environmental stress. Return loss, gain, bandwidth, efficiency, and the SAR are some of the most important parameters that define the performance of an antenna. Their interactions with human tissues are also studied in greater detail. Such studies are essential to ensure that wearable and body-centric communication systems perform optimally, remain safe, and are in compliance with regulatory standards. Advanced materials, including textiles, polymers, and conductive composites, are analyzed for their electromagnetic properties and mechanical resilience. This study also explores innovative fabrication techniques, such as inkjet printing, screen printing, and embroidery, which enable scalable and cost-effective production. Additionally, solutions for SAR optimization, including the use of metamaterials, electromagnetic band gap (EBG) structures, and frequency-selective surfaces (FSSs), are discussed. This review highlights the transformative potential of wearable antennas in healthcare, the IoT, and next-generation communication systems, emphasizing their adaptability for real-time monitoring and advanced wireless technologies, such as 5G and 6G. The integration of energy harvesting, biocompatible materials, and sustainable manufacturing processes is identified as a future direction, paving the way for wearable antennas to become integral to the evolution of smart healthcare and connected systems.

The design of a compact wideband partial slotted ground rectangular-printed antenna is presented. The design approach utilizing the slotted partial ground plane is much more flexible for improving the antenna performance. A detailed design guideline to estimate the antenna dimensions is given, which is based on mathematical and parametric analysis. The effects of variation of length of the ground and slot position in the ground plane are investigated. The simulation has been performed by using HFSS V20 simulator. The designed antenna is meant for being operated in the C band of super-high-frequency (SHF) spectrum and in the n77 band (3.3-4.2 GHz) and n78 band (3.3-3.8 GHz) of frequency range 1 (FR1) in sub-6 GHz 5G-frequency bands. The designed antenna is showing a wide bandwidth (700 MHz) with a low-reflection coefficient of −31.15 dB. The wide bandwidth and compact size of the antenna makes it suitable for use in sub-6 GHz 5G compact wireless communication systems. The measured results of the antenna prototype are firmly authenticated with simulation estimations.

In this study, the two designs of the compact microstrip patch antennas, exhibiting ultra wideband characteristics are presented. The design offers an overall bandwidth of 4.7 and 5.2 GHz with a return loss of −35dB and −40 dB, respectively. The presented designs of the antennas are targeted for applications in medical telemetry. Geometrical optimizations for the slotted rectangular patch antenna loaded with notches are carried out to enhance the bandwidth over the ultra wideband. Unlike the conventional way, the microstrip patch antenna is optimized by considering an infinite substrate. The effect of finite substrate on the bandwidth of the microstrip patch is investigated leading to better results in terms of simplicity, compact size, and bandwidth. Also, it is perceived that the partial ground plane, which is incorporated, improves the antenna’s bandwidth drastically and also the reflection coefficient. The prototype of the two presented designs is formulated by creating notches with three slots naming it to be MPA1, and the other one without slots and with only notches naming it to be MPA2 for observing the relative effect of slots and the partial ground plane on the bandwidth. A very close agreement is confirmed between the simulated and the experimental values of the reflection coefficient and the bandwidth. The maximum percentage bandwidth of 85% is attained in the case of MPA2, while a maximum gain of 2.39 dBi is achieved for MPA1, which offers flexibility to manufacturers for use.