Flexible Antennas: A Review

Abstract

The field of flexible antennas is witnessing an exponential growth due to the demand for wearable devices, Internet of Things (IoT) framework, point of care devices, personalized medicine platform, 5G technology, wireless sensor networks, and communication devices with a smaller form factor to name a few. The choice of non-rigid antennas is application specific and depends on the type of substrate, materials used, processing techniques, antenna performance, and the surrounding environment. There are numerous design innovations, new materials and material properties, intriguing fabrication methods, and niche applications. This review article focuses on the need for flexible antennas, materials, and processes used for fabricating the antennas, various material properties influencing antenna performance, and specific biomedical applications accompanied by the design considerations. After a comprehensive treatment of the above-mentioned topics, the article will focus on inherent challenges and future prospects of flexible antennas. Finally, an insight into the application of flexible antenna on future wireless solutions is discussed.

CPW-Fed Flexible Ultra-Wideband Antenna for IoT Applications

“…This is attributed to the higher permittivity of the used cylindrical structure, compared with the simulation ( = 1). An increase of decreases the resistive part of input impedance, and the reactance part becomes capacitive [ 46 , 47 ]. Nonetheless, the antenna maintains the desired application bandwidth for the UWB region, ensuring ample flexibility and mechanical sturdiness, and meeting practical IoT application requirements.…”

Full Ground Ultra-Wideband Wearable Textile Antenna for Breast Cancer and Wireless Body Area Network Applications

“…All wearable antennas operate in close proximity to the high dielectric medium of the human body or have close interaction with the human body that affects the radiation characteristics of the design. As relative permittivity increases near the human body, it affects the Q factor of the wearable design and electric flux is suppressed [ 4 ]. Antenna performance therefore degrades when the antenna touches the body.…”

Performance of Reconfigurable Antenna Fabricated on Flexible and Nonflexible Materials for Band Switching Applications

“…Research on flexible textile antennas has been reported in the open literature onbody and off-body communication applications, including materials used for textile antennas [5,6], design techniques, and modeling aspects of planar wearable antennas [7][8][9], which were studied comprehensively. Switchable antennas are highly recommended and are considered attractive due to their use in integrated circuits and applications.…”