Utilisation and tuning of the chassis modes of a handheld terminal for the design of multiband radiation characteristics

The essential role of the resonant modes of the surface current density distribution on the chassis of a small size handheld terminal for its multiband radiation properties is discussed. An easy-to-implement practical approach for chassis mode analysis by post-processing of output data from standard CEM software packages is presented. The purposeful utilization and the tuning of chassis modes for the design of multiband radiation characteristics on generic bar-type and folder-type geometries are demonstrated and numerical results are given for several canonical examples.