Wideband excitation and matching of fundamental chassis mode using inductive coupling element

It is known that the fundamental radiation mode of a mobile terminal chassis enables wideband coverage below 1 GHz. However, in theory, the bandwidth of this chassis mode extends infinitely beyond 1 GHz. In this paper, we investigate the use of inductive coupling element (ICE) to significantly increase the antenna bandwidth obtainable from the fundamental mode. Using characteristic mode analysis, a dual-ICE configuration is proposed and optimized to excite the fundamental mode, giving a simulated impedance bandwidth of nearly 100%.