Balance-fed L-type loop antenna system for handset

This paper presents (1) a discussion of the design concept of an antenna for a handset and (2) an analysis of a newly proposed L-type loop antenna system, which has a balanced structure and is fed with a balanced line and has a feature producing two polarization components. The balanced structure is constituted to reduce the effect of the currents in the handset unit. In order to confirm the effectiveness of using the balance-fed loop antenna, the current distribution for both the balanced and unbalanced antenna systems are analyzed theoretically and experimentally. Remarkable reduction in the current distribution on the ground plane in the handset for the case of the balance-fed antennas system is shown. There are two advantages in using the L-type element. One is observed in the handset in its talk position and the other is the mitigation of multipath fading. The performance of L-type loop antenna and its significance are discussed