Pattern and Polarization Diversity Antenna With High Isolation for Portable Wireless Devices

A compact two-element antenna with both pattern and polarization diversities and high isolation for 2.4 GHz WLAN application is reported. The antenna is composed of a low-profile monopole and a pair of inverted-L antennas fed by 180deg out-of-phase excitations. A prototype is fabricated and the measured S-parameters and radiation patterns are presented. The measured isolation is better than 29 dB across the required bandwidth. The envelope correlation coefficient, the mean effective gains and the diversity gain are calculated to evaluate the diversity potential of the proposed antenna.