Moment-Method Analysis of Normal-to-Body Antennas Using a Green´s Function Approach

The cylindrical wave decomposition of fields from a normal-to-cylinder point source is derived using a modified addition theorem. The fields scattered from a lossy cylinder, as an approximation of the human body, are also calculated and tabulated for use in an integral equation study of dipoles. The transmittance between two optimized radially polarized dipoles is evaluated on the body trunk surface, using the method of moments (MoM) in the 2.45 GHz ISM band. An anechoic chamber measurement is performed and the measured transmittance between two dipoles on the human body has been compared to the simulated one on the lossy cylinder. Although the abdominal cross section of the body does not have exactly a circular shape, strong similarities have been observed in their path-loss trends around the body. A very good agreement has been obtained between the dipoles transmittances provided by the analytical/MoM model, CST Microwave Studio simulations, and experiments, including interference effects attributed to the body-attached radiating waves.