Analysis of an ultra miniature capsule antenna for gastrointestinal endoscopy

An efficient miniaturized antenna used in Wireless Capsule Endoscopy is presented. Wireless Capsule Endoscopy is the best option to replace conventional Endoscopic methods. An antenna in this capsule provides definitive electromagnetic performance of the system which is used for inspection of the gastrointestinal tract (GI). The proposed antenna has a Double C-shaped Resonant Structure (DCRS) embedded with the antenna structure. This structure can introduce a strong electric response over any desired frequency and thus metamaterials with negative permittivity can be constructed. The parameters of the metamaterial are extracted to confirm its artificial behavior. The characterization of the miniature antenna is done at 2.45 GHz using coaxial cables and we obtained a simulated gain of −23 dBi and the achieved fractional bandwidth is 20.4%. This paper also explains the method for the calculation of the impedance of the isolated antenna structure without any conventional coaxial cable. This antenna design is well suited for ingestible applications as it is miniaturized and operates in the ISM band.