Circularly-polarized 4-arm curl antenna for wireless capsule endoscopy

Circularly-polarized 4-arm curl antenna for wireless in-body capsule endoscopy (WCE) application at 2.4 GHz is presented. The antenna arms are sequentially fed to enhance the circular polarization characteristics. The antenna is encapsulated and implanted in the human body. The human body tissue is demonstrated by a cylindrical multilayer model to simulate its dispersive properties. The full structure is simulated using the finite integral technique. The radiation characteristics of the encapsulated 4-arm curl antenna inside the human body are investigated. The orientation of the WCE inside the human body is demonstrated. The performance of the capsule in free-space with the same dimensions is investigated. The effect of capsule orientation during its travel through the digestive tract on the gain and radiation efficiency has been investigated.