Tunable antenna techniques for compact handset applications

Today's handset antenna needs to support many more bands complying with the standards specifications, yet still within the handset confined form factor. This study presents novel tunable antennas techniques. The antenna tuning here is achieved by loading the antenna aperture. Different loading types, topologies and placement options for optimised performance are investigated leading to design recommendations and guidelines. These are used in the successful design of two planar inverted-F antenna-based handset antennas with a low band tuning range of 620–950 MHz and a high band tuning range of 1.5–2.1 GHz. The designed tunable antennas are miniaturised in the process while maintaining very good radiation performance.