In this dissertation, multiband ground antennas for slim handsets are presented. The design techniques are on efficiently exciting the resonant modes of the system ground plane of the handset to greatly enhance the antenna¡¦s operating bandwidth. The first antenna design is a monopole antenna integrated with a slot antenna formed in a clearance in the system ground plane to enhance the bandwidth of the antenna¡¦s lower band for penta-band WWAN operation. The second antenna design uses a shaped circuit board with a proper notch embedded therein to result in stronger surface current excitation in the ground plane, which leads to bandwidth enhancement in the antenna¡¦s lower band and upper band. The second antenna design can cover seven-band WWAN/LTE operation. The antenna geometry in the second antenna design is further applied in the third antenna design. In order to meet the practical application of slim handsets, the third antenna design is integrated with a battery element and a metal midplate to decrease the thickness of the handset. The third antenna design can cover seven-band WWAN/LTE operation. Finally, the simulated SAR and HAC results are analyzed for the three proposed antennas.