Small spiral antenna for wideband capsule endoscope system

Abstract

A small antenna for the wideband capsule endoscope system is proposed. Since the capsule endoscope system works in the body and transmits internal image data to a receiver with high resolution, a small wideband antenna is required. To obtain wideband characteristics, a small spiral structure is applied. The proposed antenna has size of 10.1 mm diameter and 3 mm height. The electrical properties of the human body with dielectric constant of 56 and conductivity of 0.83 are considered. The impedance bandwidth of the proposed antenna is from 430 to 500 MHz for VSWR<2 and it has isotropic radiation pattern.