Performance of MIMO-enabled portable devices is heavily dependent on the characteristics of its antenna arrays -. A typical MIMO antenna array for portable devices should have compact structure, high radiation efficiency, and low spatial correlation in addition to the required bandwidth and nearly omni-directional radiation pattern. Various MIMO antenna arrays for portable devices have been reported in the literature where mostly the frequency of interest is either 2.4 GHz or 5.2 GHz -. In this paper, design and experimental characterization of a four-element PIFA array for MIMO-enabled portable devices is presented. Basic element of the array is a compact PIFA structure with a volume of 0.16 cm. PIFA elements are symmetrically located at the corners of a rectangular PAD-sized ground plane. The antenna array is initially characterized by measuring scattering parameters and radiation patterns at the individual antenna ports. In order to measure channel impulse responses, indoor MIMO measurements under line-of-sight (LOS) and non-line-of-sight (NLOS) propagation conditions are then performed for a linear array of monopoles and the PIFA array. The measured channel data is then post-processed to evaluate spatial correlation and capacity for the two arrays. Power azimuth spectrum (PAS) at LOS and NLOS locations is estimated to determine the angle-of-arrival information for the significant multipaths. Capacity and spatial correlation for the PIFA array under both propagation scenarios are compared to that of the standard quarter-wave monopole array.