Performance of internal microstrip handset antennas

Large bandwidth and small size are the most critical properties of small handset antennas. The bandwidth of a resonant antenna is shown to increase by adding resonant circuits into the matching circuit. The bandwidth and front to back ratio are studied as a function of the ground plane size of a quarter-wave patch antenna at about 1.8 GHz. Finally the effect of the hand of the user on the matching and resonant frequency of the antenna are measured.