Orientation Insensitive Antenna With Polarization Diversity for Wireless Capsule Endoscope System

摘要

An orientation insensitive antenna is proposed for the 2.4-GHz industrial, scientific, and medical band wireless capsule endoscopy system. To achieve the polarization diversity, three orthogonal currents are obtained by bending a dipole. Inversed T matching branch and meander lines are employed to gain better impendence matching and miniaturization. A normal dipole in capsule with single polarization is set as the reference antenna in simulation. The one-layer muscle phantom and the Gustav human body model are adopted in simulation. Minced pork is used during measurement. Communication links between the proposed capsule antenna and the external receiving antenna when they are in different orientations are measured to demonstrate the advantages the polarization diversity brings. According to the measured |S21| , the proposed antenna can transmit effectively even the orientation of the capsule is changed; therefore, direction insensitivity performance is achieved.