The requirement of mounting several access points and base stations is increasing tremendously due to recent advancements and the need for high-data-rate communication services of 5G and 6G wireless communication systems. In the near future, the enormous number of these access points might cause a mess. In such cases, an optically transparent antenna (OTA) is the best option for making the environment more appealing and pleasant. OTAs provide the possible solution as these maintain the device aesthetics to achieve transparency as well as fulfill the basic coverage and bandwidth requirements. Various attempts have been made to design OTAs to provide coverage for wireless communication, particularly for the dead zones. These antennas can be installed on building windows, car windscreens, towers, trees, and smart windows, which enables network access for vehicles and people passing by those locations. Several transparent materials and techniques are used for transparent antenna design. Thin-film and mesh-grid techniques are very popular to transform metallic parts of the antenna into a transparent material. In this article, a comprehensive review of both the techniques used for the design of OTAs is presented. The performance comparison of OTAs on the basis of bandwidth, gain, transparency, transmittance, and efficiency is also presented. An OTA is the best choice in these situations to improve the aesthetics and comfort of the surroundings with high antenna performance.

Several research articles are available in the literature regarding the design of antennas, but hardly (to the best of authors’ knowledge) few papers covered the antennas that are designed for the detection, diagnostics, and monitoring of various diseases. There is a need for a research article in which the design and performance of such significant antennas should be compared and highlighted based on various available design techniques to enhance performance parameters that include efficiency, bandwidth, size and appropriate bio-compatible material used to transmit data from the human body efficiently. Antennas are essential in biomedical applications for wireless communication, miniaturization, integration, implantable devices, diagnostic imaging, biotelemetry, and biosensing. They enable efficient and reliable wireless connectivity, facilitating remote monitoring, improving patient care, and advancing medical research. Designing biomedical antennas presents several challenges, including miniaturization and integration into compact devices, ensuring biocompatibility with the human body, conforming to biological structures, mitigating electromagnetic interference (EMI), accounting for signal attenuation and propagation in the body, optimizing power efficiency, and ensuring compliance with regulatory standards. Overcoming these challenges requires expertise in antenna design, biocompatibility, electromagnetic modelling, and collaboration between disciplines. Therefore, a detailed review is required so that any scholar who wishes to excel in this field may read this review to understand future directions better and work already done for the design of biomedical antennas. This review comprises a comparison of several significant biomedical antenna design techniques used for the detection, diagnosis and monitoring of various diseases, which can be helpful for the medical community for the detection of various diseases, including skin cancer, breast cancer, lungs cancer, endoscopy, brain tumor and glucose level detection. The various features of biomedical antennas are thoroughly investigated to provide performance metrics of the antennas designed to diagnose various diseases. The advantage of this study is the understanding of different types of antennas for various diseases. This study also allows realizing appropriate bio-compatible materials and flexible materials for biomedical antenna design, the effect of Specific Absorption Rate (SAR) on human/animal body and finally, the tables provide the antenna performance in terms of gain, bandwidth, and directivity with respect to antenna size and type of substrate material used for each disease. These biomedical antennas have several applications for diagnosis, early-stage cancer detection and, in some cases providing enough energy to cure the cancer cells in the human/animal body. Moreover, the implementation of Machine learning algorithms for the early detection of tumor for the above-mentioned diseases is also discussed.

This work presents an optically transparent and flexible MIMO antenna that features two square patch elements placed in close proximity, aiming to meet the demands of compactness, flexibility, optical transparency, and visual appeal for IoT applications and future 5G wireless communication. The design includes a simple offset fed configuration to achieve the required isolation and impedance matching. It simplifies the process of creating closely spaced transparent MIMO antenna configurations. By optimizing and analyzing this structure, the antenna achieves better isolation and diversity gain performance, even when the patch elements are positioned very close to each other. To achieve optical transparency and flexibility, the antenna uses thin polyethylene terephthalate (PET) material as a substrate, which is a thermoplastic polymer resin from the polyester family. The wired metal mesh parameters for conducting parts of the MIMO antenna and offset position of the feed are carefully optimized to achieve required optical transparency, isolation, impedance matching and radiation performance without any complex decoupling or impedance matching network.

An optically transparent MIMO antenna with close proximity two-element square patch antenna elements has been presented here to achieve forthcoming requirements of compactness, optical transparency and visual aesthetic for 5G wireless communication and Internet of Things (IoT) applications. A simple, thin optically transparent and more innovative decoupling structure with easier to design closely spaced transparent MIMO antenna configuration is proposed, optimized, and analyzed to achieve higher isolation and diversity gain performance even with close proximity of patch antenna elements. Polyethylene terephthalate (PET) material, which is thermoplastic polymer resin of the polyester family is used as a substrate to achieve optical transparency. The wired metal mesh parameters are taken into consideration to achieve required optical transparency as well as isolation and radiation performance for the MIMO antenna. The performance of the proposed MIMO antenna is also verified through fabricated prototype.