The radiation characteristic of a lambda /4-monopole antenna mounted on a conducting body with a notch (portable telephone model)

The authors describe the radiation characteristic and the current distributions of a lambda /4-monopole antenna on the conducting body modeled as an ordinary portable telephone by simulation using the time domain method. The results show that the current on the conducting body has an undesirable influence on the radiation of the antenna. A novel method is proposed to prevent such an undesirable influence by cutting a notch in the conducting body. In terms of the radiation characteristic of the model with such a notch, the results of simulation and an experiment agree and indicate good performance.<>