Miniaturization Design of the Antenna for Wireless Capsule Endoscope

This paper analyzed the type of mini-type antenna, studied the miniaturization technique, and simulated the performance of antenna with tissue. Monopole antenna possesses wide-band frequency characteristic and high radiation efficiency. It is easy to be designed and manufactured with guarantee consistency, but with the fatal flaw of a large size. Helical antenna can provide sufficient bandwidth for transferring data, generate circular polarized wave. It can reduce the axial size to sixty percent, but must be with comparatively big radial dimension to acquire the excellent performance. The advantages of micro-strip antenna are light weight, compact size, relatively thin thickness, and so on. And the last kind of antenna still requires aggressive miniaturization to meet the requirements of the wireless capsule endoscope. Techniques for miniaturization of antenna mainly include a ground plane, double-layer patch, shorting pin or wall, lossless high dielectric substrate, and the spiral structure. The influence of humane tissue on the antenna behavior must be considered. So the relationship between the antenna and issue was analyzed in this article to improve the antenna characteristic such as return loss, input impedance and standing wave ratio.