Research On Wearable Antenna Sensor Based On Metamaterial Structure

With the rapid development of wireless body area network and wearable electronic devices,wearable electronic devices have been widely used in entertainment,leisure,location tracking,health management,sports monitoring,medical assistance and military fields.Wearable antenna sensors are of great interest to researchers because of their wireless transmission,small size and low cost.Adding metamaterials to the antenna not only reduces the SAR value of the antenna to the human body,but also increases the forward radiation of the antenna,making the performance of the antenna more stable.The main work in this paper is as follows:(1)A wearable coplanar waveguide pressure sensor antenna based on the electromagnetic band gap(EBG)structure is designed.The reflection phase characteristics of EBG are studied,and the parameters of the antenna with or without EBG are analyzed.When the antenna is bent with the human body,the performance of the antenna remains good.When the antenna pressure sensor is connected to the vector network analyzer,the resonance frequency of the antenna will shift with the increase of the pressure.The sensitivity of the antenna sensor to the pressure is 11 MHz/N.(2)An antenna working at 2.45 GHz wearing human neck is designed,with 2placed between antenna sensor and neck × 2 The electromagnetic band gap(EBG)array reduces the specific absorption rate(SAR)of the human body by about 90% and increases the peak gain from 2.46 dBi to 6.75 dBi.Even though the antenna sensor is severely bent,the gain characteristics of the antenna sensor remain good.The efficiency of antenna sensors loaded with EBG arrays is maintained at 65%,and the resonance frequency of antenna sensors is offset when the human body bends.Based on this feature,antenna sensors can be used to monitor the cervical curve.The sensitivity of antenna sensor to bending angle is 7.5MHz/1°.