Comparison of FDTD computed and measured radiation patterns of commercial mobile telephones in presence of the human head

The finite-difference time domain (FDTD) computed radiation patterns of mobile telephones are carefully compared with those measured in our laboratory. The question of the capability of the FDTD method to correctly predict the radiated electromagnetic fields of today's structurally complex mobile telephones is addressed. Two commercially available cellular telephones equipped with two different antennas (one helix and one helix monopole) are considered and the radiation patterns are measured and the FDTD computed with and without the human head. The FDTD computed and measured radiation patterns show good agreement. This verifies that numerical techniques are suitable for accurately modeling the radiation patterns of realistic cellular telephones and, more importantly, that the FDTD method is a valid alternative to measurements in the design of new cellular telephones.