Dual-feed ultra-compact reconfigurable handset antenna for penta-band operation

This paper proposes a very small (lcc) dual-feed reconfigurable antenna concept. The circuit layout of the dual-feed antenna system is shown in Figure 1(d). Since the low bands are more challenging to cover with a passive antenna, the frequency reconfigurability is more important there. Therefore, at the low band the antenna consists of a radiator element, a RF switch together with matching network to obtain a frequency-reconfigurable antenna system. The trade off is the complexity and loss which is introduced by the switch and matching network. At the high bands (DCS1800, PCS1900, WCDMAI) the antenna is electrically larger and will operate more independently of the phone chassis. Furthermore, the efficiency requirements are usually higher for the high bands. Therefore, the high bands are covered using a radiator element with matching network in order to reduce complexity and loss.