Improvements of impedance and radiation performances with a parasitic element for mobile phone

In this paper, novel usage of a parasitic element is proposed. This approach creates a kind of 3lambda/4 length antenna. Proposed antenna improves input impedance with wider bandwidth as well as its radiation patterns in both free space and handhold environment. A parasitic lambda /4 element is attached at an opposite side of corner which is roughly lambda /4 away from the feeding point. By this layout, its input impedance improves and influence from user hand is minimized at holding position. Through various analyses, overall performance of the proposed antenna shows better than that of conventional antenna without a parasitic element since leakage current on its ground plane is reduced and dominant radiating part is set away from user hand.