Basic Performances of Handset MIMO Antenna using L-shaped Folded Monopole Antennas

In the previous study [1], a built-in L-shaped folded monopole antenna (LFMA) has been proposed and its fundamental performances have been analyzed and compared with those of PIFA, taking application to the handset MIMO system into consideration. The LFMA has been found to have similar bandwidth (the relative bandwidth for VSWR≤2 was about 19% at the frequency of nearly 2GHz) and the physical volume was miniaturized up to about 44% of PIFA. The purpose of this study is to evaluate the basic performances of handset MIMO antenna comprising two LFMAs mounted on a finite ground plane (GP), under practical use conditions, involving multipath radio wave propagation environment. The fundamental antenna characteristics will be analyzed both theoretically and experimentally, at the first, and then the mean effective gain (MEG) and the correlation characteristics between the two antenna branches will be estimated theoretically with regard to the handset inclination angle from the vertical. In the estimation of the MEG and correlation characteristics, the same method and propagation conditions are used as the literature [2], [3]. In the theoretical analysis, the electromagnetic simulator based on the Finite Integration Method (FIM) is used.