Human effect on twin antenna on-body for three diversity techniques at 2.4 GHz

Abstract

Since the user is generally in the near field On-body antennas are accepted as more complex to optimise than their free space counterparts. Use of the body as a platform for wearable electronics is a topical subject. Omnidirectional antennas are thought to be useful for antennas in body area networks. However, the desirable properties of omnidirectional radiation patterns close to humans are severely diminished due to the lossy load nature of biological matter and high levels of scattering due to shadowing and mismatch. To alleviate these problems two or more antennas can be used on the body. In this paper, two on body antennas are used with three different combination techniques in order to evaluate the diversity performance and then compared with their free space equivalents. Three diversity techniques are used – Selective, Maximal Ratio and Equal Gain. The frequency of operation was 2.4GHz.