A Study on the Over-The-Air Method for Evaluating BAN Antennas

1. Introduction This paper presents a new methodology for realizing a Rice channel in BAN Over-The-Air (OTA) testing using a fading emulator with a dynamic phantom. For the proposed apparatus to be effectual, the fading emulator must be provided with an appropriate K-factor that represents the actual propagation environment indoors. Further, an implementation of the Rice channel to the proposed fading emulator in a BAN situation is presented. Thereafter, a calibration method for the fading emulator to adjust the actual K-factor of the on-body Rice channel is advanced. This calibration method is validated by analyzing the variations in the instantaneous K-factor attributed to the arm-swinging motion. Finally, an experiment is conducted for a continuous human walking motion with the fading emulator using an arm-swinging dynamic phantom. The results show that the actual Rice channel propagation environment considering dynamic characteristics of human walking motion can be realized in BAN-OTA testing with the developed fading emulator 2. Calibration Method Fig. 1 shows the configuration of BAN fading emulator [1]. It can be calibrated by setting the values of the attenuators, using Eqs. (1) and (2) given below.