Wideband slot antenna for low-profile hand-held terminal applications

A quarter-wave transversal slot in the center of a handheld terminal ground plane is proposed and evaluated as a wideband antenna for low profile mobile phones. By feeding the slot with a microstrip line, a triple-resonance response is obtained from the chassis, slot and microstrip stub interaction, providing sufficient impedance bandwidth and radiation efficiency to cover the 0.9-2.7 GHz frequency range. While the introduction of a slot in the ground plane has many advantages over e.g. PIFA or patch structures, both in terms of performance and cost, the circuit floor planning becomes more complicated. To address this problem, a possible solution in terms of module partitioning and signal line routing is suggested. In addition, simulations of parasitic antenna to signal line coupling and techniques to reduce this effect are presented.