Tunable antennas for mobile devices: Achieving high performance in compelling form factors

The evolution of modern mobile terminals has been driven by two key factors, the user interface and broadband connectivity. However, while the peak performance near the base station may be state-of-the-art, real world performance (in-building, in suburbs and rural areas, in-car and on-person) has substantially fallen over the years. This has not only impacted achievable data rates and reduced battery life but, in many cases, actually prevented useful connections for voice or data. The key factor driving this degradation has been changing antenna location and reduced antenna volume driven by the race for thinner and display-dominated platforms. Reduced antenna volume leads to a tradeoff between bandwidth and efficiency. To maintain acceptable efficiency, tunable and reconfigurable antennas are being deployed to enable effective use of reduced instantaneous bandwidths. This capability brings new challenges as well as new opportunities to the handset designer.