An integrated circuit (IC) for decoupling of multiple-input multiple-output (MIMO) antennas as well as for aperture and impedance tuning is demonstrated in this paper. The IC decouples the adjacent stripes of the inverted-F antenna (IFA) forming the two separate IFAs for MIMO operation in middle- and high- cellular frequency bands. For low-band operation the IC joins the stripes, forming a single IFA with double the physical length. The same IC is also used for impedance and aperture tuning of the antennas. The IC is designed and fabricated in dedicated 130 nm RF switch technology. The design and measurement results are presented in the paper.