Dual-feed PIFA diversity antenna for wireless applications

A novel dual-feed planar inverted-F antenna (PIFA) suitable for wireless diversity/MIMO applications is presented. By exploiting the pattern diversity, successful provision of two isolated feeding ports using one common radiating plate has been achieved. The main technique introduced is to etch the ground plane under the radiating plate to reduce the mutual coupling between the two ports. It is found that the envelope cross-correlation is less than 0.02 and the ratio of the mean effective gain between the two ports is close to unity. Thus, this new PIFA antenna can provide a better solution than two separate antennas for diversity and MIMO applications by saving space and cost. Simulated and measured results verify the conclusion.