Some thoughts on human body effects on handset antenna at the FM Band

Human body interaction is an important issue to take into account when designing handset antennas due to the effect that it has on the electromagnetic performance of the antenna. By means of electromagnetic simulation, three different antennas (a 1-meter length monopole and two small handset antennas) in three different situations (free-space, hand holding, and in pocket position) have been analysed at the FM band (88 MHz-108 MHz). Results prove that it is possible to predict the antenna behaviour in terms of quality factor (Q) by assessing the variations of the near electric field and the radiation e±ciency in said environments. The estimated Q can be verified by calculating the Q using the input impedance. Results show that human body may improve the efficiency when the antennas become an extension of the human body.