A Planar Windmill-Like Broadband Antenna Equipped With Artificial Magnetic Conductor for Off-Body Communications

A broadband antenna inspired by a windmill sail is developed for wireless body area network (WBAN) applications. The antenna consists of a couple of modified dipoles with four crossed symmetrical S-shaped arms printed on a flexible substrate. A 5 ×5 unit structure of artificial magnetic conductor (AMC) is integrated to reduce the backward scattering wave toward the human body, and simultaneously ensures a low profile with a thickness of 5.74 mm and a small size with the area of 46 ×46 mm2. The measured results on the phantom reveal that the AMC-integrated antenna accomplishes an impedance bandwidth of 63.5% (5.7-11.0 GHz) with , a peak gain of 8 dBi, and a front-to-back ratio (FBR) greater than 15 dB. Health safety factors, such as specific absorption rate and temperature, are considered. According to the calculation of link budget in different scenarios, the reliable communication can be guaranteed within 10 m in line-of-sight (LOS) environment. The good performances make the proposed AMC-integrated antenna potential for wireless communication between miniaturized wearable sensors and a localized base station around body.