ABSTRACT
Development of mobile communications has drastically changed the handset antenna design landscape. The handset antenna design target has changed from gain and radiation pattern to system efciency and better user experience for multiband and multimode applications. The traditional approach in passive multiband antenna design is to trade antenna efciency with bandwidth. Antenna tuning was proposed to address the multiband requirements. There are two ways to tune the antenna for multiple band operation: impedance tuning and aperture tuning. Antenna tuning has become practical in handsets with recent advancements in radio frequency (RF) tuning components: varactors, MEMS tunable capacitor, pin-diodes, RF switches, and so on.
