Design of a Compact Tri-Band PIFA Based on Independent Control of the Resonant Frequencies

The application of multiple folded radiator to independent frequency control of a compact tri-band planar inverted-F antenna (PIFA) composed of three resonant frequencies, global system for mobile communication (GSM900, 880-960 MHz)/digital communication system (DCS1800, 1710-1880 MHz)/Satellite Digital Mobile Broadcasting (Satellite DMB, 2605-2655 MHz) are treated with the optimized parameter values. The proposed antenna has been designed and analyzed by using commercially available softwares, CST MWS based on the finite-difference time-domain algorithm, High Frequency Structure Simulator (HFSS) based on the finite element method algorithm and a simple resonant equation, respectively. It is also seen that good isolation characteristics and independent frequency control can be accomplished by using the separation of folded parts operating at each different frequency. In addition, the return loss has been measured and compared between measured and simulated data under the criterion of VSWR less than 3. The radiation patterns in each service are the same as the omnidirectional characteristics and the maximum gains are 1.19, 2.93, and 1.48 dBi at 0.92, 1.8, and 2.63 GHz, center frequencies of each service, respectively.