WBAN Radio Channel Characteristics Between the Endoscope Capsule and on-Body Antenna

This paper presents a study on the radio channel characteristics between an endoscope capsule and an on-body antenna in different parts of the small intestine with different on-body antenna location options. The study is conducted using finite integration technique based electromagnetic simulation software CST and one of its anatomical voxels. An endoscope capsule model with a dipole antenna is set inside different areas of the small intestine of the voxel model. A recently published highly-directive on-body antenna designed for on-in-body communications is used in the evaluations. Different rotation angles of the capsule are also considered both with a layer model and a voxel model. It is found that radio channel characteristics vary remarkably depending on the antenna location in the small intestine and location of the on-body antenna. Thus, the on-body antennas should be located carefully to ensure coverage over the whole intestine area. However, the path loss does not only depend on the distance between a capsule and the on-body antenna but also on the tissues between the capsule and on-body antennas. Furthermore, orientation of the capsule has also strong impact when linearly polarized antennas are used.