Decoupling method between two L-shaped folded monopole antennas for handsets using a bridge line

This study analyses the reduction of mutual coupling between two L-shaped folded monopole antennas (LFMAs) operating at 2 GHz on the finite ground plane. Firstly, the change in mutual coupling with respect to the spacing between the two elements in two array models is investigated and the effects on the antenna efficiency are studied. Subsequently, the authors proposed an effective method to reduce mutual coupling by using a bridge line that links two antennas. From the viewpoint of mutual coupling and total antenna efficiency, it is desirable to place shorting strips of both LFMA elements in such a manner that they face each other. Moreover, drastically reduced mutual coupling and improved total antenna efficiency can be obtained by linking two feeding strips with a bridge line.