The Key Technologies Research Of Dielectric Resonator Antenna For Wireless Capsule Endoscope Application

Traditional medical examination equipment,such as gastroscopy,causes unbearable suffering to patients in the process of checkups.Therefore,the patient has to be given a general anaesthesia before checkups.Wireless Capsule Endoscopy System（WCE）,as a highly integrated miniaturized digestive tract examination equipment,consists of micro camera,LED,Wireless IC transmitter and antenna,etc.The small size of the wireless capsule endoscope requires a highly integrated,miniaturized antenna.The antenna is mainly responsible for transmitting the digestive tract data and images collected by capsule endoscope system to the body.Capsule endoscope antenna also needs to have the characteristics of low power,high efficiency and quasi-isotropy because the position and direction of the capsule are not fixed.The existing metal capsule endoscope can’t meet the requirements,In order to solve this problem,compact,high-gain,quasi-isotropic capsule endoscope antennas based on dielectric resonator is studied in this paper.In this chapter,a hollow cylindrical quasi-isotropic dielectric resonator antenna is proposed.The HEM_11δmode of the DR and TM₁₀ mode of the floor are excited by digging hole in the center of the cylindrical dielectric resonator antenna.The two modes with a radiation pattern are orthogonal.It is equivalent to a magnetic dipole and an electric dipole.Thus achieving the quasi-isotropic radiation characteristics.The antenna is fed by a coaxial probe and works in the 5.8-GHz Industrial,Scientific,and Medical（ISM）bands.The simulation results show that the antenna has characteristics of quasi-isotropic radiation pattern and high gain.On this basis,a conformal hemispherical quasi-isotropic dielectric resonator antenna is proposed.Compared with the previous structure,the antenna has better quasi-isotropic performance and can conformal to the hemispheric shell at both ends of the capsule to save the internal space of the capsule.The experimental results show that the bandwidth of the antenna is 3.20%,the maximum efficiency is 8.15%,the maximum gain is-8 dBi,and the gain deviation is 9.0 dBi.This study shows that the capsule endoscope antenna based on dielectric resonator has the excellent characteristics of miniaturization,strong anti-interference performance,low loss,high efficiency and quasi-isotropy.