Frequency tunable antenna using coupling patterns for mobile terminals

A frequency-reconfigurable antenna based on aperture tuning using a coupled aperture structure on which a digital variable capacitor (DVC) is connected is presented. The coupled aperture structure is used to avoid electrical contact between the antenna radiator and the DVC in order to reduce antenna efficiency degradation due to ohmic losses at the DVC. The operating frequency is 700 MHz where the antenna efficiency is sensitive to the ohmic loss in the DVC. Analysis based on measurements and simulation confirm the benefits of using the coupled aperture structure over the conventional aperture tuning. It is shown that the coupled aperture plays a key role in reducing the impact of the equivalent series resistance of the DVC component on the antenna efficiency at 700 MHz.