Decoupling of Four Closely Spaced PIFAs Using Parasitic Elements and Bridge Lines

This study proposed a simple decoupling method for four planar inverted-F antennas (PIFAs) operating at 2.0 GHz (f0) using parasitic elements (PEs) and bridge lines (BLs). The edge-to-edge spacings of the adjacent PIFAs is extremely small, resulting in strong mutual coupling among them. The simulated results showed that loading the proposed PEs and BLs onto the four PIFAs could reduce as well as maintain all mutual coupling for less than -10dB, which are acceptable levels for MIMO antennas, and simultaneously improve impedance matching. Therefore, the total antenna efficiency at 2.0 GHz could be significantly improved from 64.2% to 84.8% for PIFAI and PIFA4 and from 35.9% to 74.2% for PIFA2 and PIFA3.