Radiation Efficiency of Several Handset Antennas Obtained with a Modified Wheeler Cap Method

The radiation efficiency of four different antenna prototypes, measured with a generalized Wheeler cap method is presented. With these measurements, two different goals are intended: 1) the validation of the measurement procedure and 2) the characterization of the envisaged prototypes. The antennas have been chosen in order to test the influence of both cap and antenna resonances in the measurement procedure. Three of the prototypes have been designed to be used in small handsets while the forth one has been printed in a lossy dielectric.