Multiband non-resonant antenna system with reduced ground clearance

Small and multiband antennas are crucial elements for wireless devices. On one hand, the space devoted to the antenna is small due to the presence of other electronic components in the device. On the other hand, the number of frequency bands with the inclusion of 4G is relevant. In order to achieve a small and multiband antenna, a strategy using a non-resonant element in combination with a passive multiband matching network is proposed. Also, in order to facilitate the integration of other electronic components in the device, the ground clearance is reduced and its impact on efficiency has been evaluated. The feasibility of the proposal is analyzed both in the simulation domain as well as with a prototype to validate the results. The proposed architecture comprises a non-resonant element of 12 mm × 3 mm × 2.4 mm (h) operating at 824MHz-960MHz and 1710MHz-2690MHz with a ground clearance of 20 mm × 11 mm suitable for smartphones.