Characteristics of a dipole antenna built-in a flip of a portable telephone

Abstract

We have proposed the new type of the antenna for the portable telephone built in the 'flip'. This antenna is composed of parallel lines and a dipole built-in 'flip'. The parallel lines are excited with out-of-phase and in-phase when the 'flip' is opened and closed, respectively. When the 'flip' is closed, i.e. on standby, we used the in-phase excitation of the feed lines to cause the induced current on the box. This current can improve the bandwidth under the closed 'flip' condition. When the 'flip' is opened, i.e. set near the human body for use, we used the out-of-phase excitation to keep the radiator away from the human body. The much higher efficiency can be obtained than that of the conventional monopole antenna. We verify the characteristics of the antenna with the FDTD method. The calculation is done at 2 GHz.