On-Body Transmission at 5.2 GHz: Simulations Using FDTD With a Time Domain Huygens´ Technique

On-body communications systems are heavily influenced by the effects of the human body and cannot be analyzed without taking these into account. This, however, leads to a large problem which is a challenge to model. In this paper a transmission scenario is modeled which includes transmit and receive cavity backed slot (CBS) antennas on the body of a male adult. The slots are backed with cavities in order to get unidirectional radiation patterns and decrease the near field body interaction of the slots. The scenario is simulated with finite difference time domain (FDTD) method in combination with a time domain Huygens´ (TDH) technique in order to reduce the computational load. A cylindrical numerical phantom including 15 different tissue types is modeled to represent the upper body of a male. The predicted transmission coefficient, return loss and radiation patterns obtained using the TDH method are shown to be in agreement with the resource intensive direct FDTD approach but are obtained in approximately 30% of the time.