Novel Compact Quasi-Dipole Diversity Antenna for Mobile Terminals

A novel compact quasi-dipole dual-element antenna for a diversity system is proposed and studied. The antenna, consisting of two symmetric quasi-dipole elements, adopts 3-D structures to make the whole antenna system compact for mobile terminals. Based on optimized simulation results, a prototype of the proposed antenna is fabricated and measured. It has a -10-dB impedance bandwidth of 450 MHz (2.32-2.77 GHz), covering the 2.4-GHz WLAN (2400-2483 MHz) and 2.5-GHz WiMAX (2500-2690 MHz) bands, and across the whole band, the isolation between the two elements is higher than 17 dB. The measured radiation patterns tend to cover complementary space. Then, the evaluation of the diversity performance is conducted by calculating the envelope correlation coefficient, the mean effective gains, and the diversity gain using the measured data. Results show that the proposed antenna can be applied in diversity systems.