Design consideration and recent developments in flexible, transparent and wearable antenna technology: A review

Abstract

The wearable technology and flexible electronics have been convoluted in modern technologies and many of applications especially insensors, biomedical, displays, solar panels, glasses, smart cities, integrated circuits, and wireless body area network (WBAN). They offer capability of mechanical deformation conditions mainly stretchable, bendable, foldable features and capable to severe environmental conditions. Nowadays, a device having lightweight, low‐profile, compact in size and flexible deployment on the system platforms is preferred. With the flexibility in the design of the antenna, they require flexible, robust, easy to wear, visually imperceptible, unobtrusiveness, and planar material for the realization. The characteristics of the wearable antenna may vary according to the material conductivity and their optical transparency, substrate selection and their thickness along with permittivity opted for and mechanical deformation behavior. Generally, the textile material is utilized to design the flexible wearable antenna due to material flexibility which can minimize the losses and enhance the antenna performance. Conversely, the visually imperceptible and flexible material is utilized to design transparent wearable antenna due to appropriate trade‐off between conductivity and optical transparency of the materials. For diverse WBAN applications, the flexible, transparent, and wearable antennas are utilized. This paper elaborates the comprehensive review and the state‐of‐the‐art research on the diverse categories of the wearable antennas based on the substrate characteristics such as flexibility and transparency. In addition, it provides the broad investigation of the flexible and transparent materials utilized to design wearable antennas and different tissue layers with their dielectric properties to develop the human multilayer phantom model.

Evaluation of Antenna Designs for Wearable Technology: A Literature Review

“…Their key properties include elastic, flexible, and foldable, and they can withstand harsh weather conditions. They can also withstand mechanical deformation [10]. The functionality of a wearable antenna, an essential component of the radio frequency front-end of wearable devices, directly influences the ability of the human body's wireless communication system to function correctly.…”

Design of Enhanced Wide Band Microstrip Patch Antenna Based on Defected Ground Structures (DGS) for Sub-6 GHz Applications

“…However, the miniaturization of MPAs poses significant challenges, particularly in maintaining performance efficacy. To address these, researchers have identified three primary methodologies for miniaturizing MPA which include slot integration, shorting and folding techniques, and material loading [2]. The first method (introducing slots) involves decreasing the antenna's size by adding slots or modifying its shape, aiming to maintain substantial electrical length in a smaller area [3][4][5], in this method, the design parameters of slots and shape can be optimized using genetic algorithms [6][7][8].…”

Design and Measurement of a Compact Millimeter Wave Highly Flexible MIMO Antenna Loaded With Metamaterial Reflective Surface for Wearable Applications

“…There are various flexible substrates used in the literature to design antenna, such as felt-textile [2], liquid crystal polymer (LCP) [8], silicone rubber [27], polyester [29], jeans [30], etc. The detailed analysis of flexible substrates is presented in [31]. Out of these, the polyimide substrate has gained attention in the early 90s to design microcircuits for biomedical applications [32].…”