Flexible Substrate based Printed Wearable Antennas for Wireless Body Area Networks Medical Applications (Review)

Abstract: The wireless body area networks (WBAN) enable to communicate with the on-body wireless devices and systems. For on-body applications, the key requirement for the antennas is the antennas flexibility to mount the antennas on the body. Wearable antennas are fabricated on a flexible substrate to make these antennas suitable for mounting on the human body. Due to the wearable feature of these antennas, they are used in many on-body applications. The wearable characteristic also makes these antennas suitable for many on-body medical applications. This paper presents the technical review of the WBAN, WBAN frequency bands, wearable antenna fundamentals, flexible substrate characteristics, design and development of wearable antennas for medical applications. The wearable antennas are fabricated using the fabrics. The review of the material properties of various flexible substrates is given in detail. Due to the presence of the air in the gaps of fabrics, the dielectric constants of these materials are very low. Detailed analysis of antenna performance due to flexible substrate material characteristics is also discussed. The developments of wearable antennas for WBAN medical applications are presented. The paper also focuses on the design considerations, fabrication methods, challenges, and proposed solutions for the wearable printed antennas.