Electrically tuned antenna for 4G mobile communication

An electrically tuned antenna for mobile handsets working in four low and one high LTE frequency bands is described. The PIFA-type antenna contains high and low-frequency branches. A tuning element is connected to the low-frequency branch. The proposed antenna operates at one of low-frequency bands depending on state of the tuning element, keeping tuning on the high-frequency band. A varactor and a PIN diode were used as a tuning element. Analysis of simulation results showed that the varactor diode provides better performance than PIN diode. The required tuning can be easily covered by changing varactor voltage from 0 to 4 V, available from the battery of mobile handset with minimal power consumption. Simulation has been performed using RFS computer code.