Free access transmission line for body centric communication (Invited)

A free access transmission line consisting of band pass filter and microstrip line is proposed for body centric communication. The subsidiary flexible waveguide on body surface is another option for on-body communication with high security and small transmission losses. A sheet-like flexible 2-D waveguide provides free access by any type of antennas in any positions, however its propagating cylindrical wave causes large transmission losses. By limiting the coupling position on body surface, the microstrip line is replaced by 2-D waveguide and discrete electromagnetic coupling structure gives easy access to the transmission line network on the body surface. The transmission lines are connected by a band pass filter with symmetric geometry which couples to any antennas placed on the above. This paper describes this novel transmission line and its applications.