This　article　presents　a　wideband　printed-monopole　antenna　pair　with　enhanced　isolation.　A　clear　two-step　method　based　on　even-mode　(EM)　and　odd-mode　(OM)　analyses　is　developed　for　antenna　decoupling　and　matching:　first,　the　OM　input　impedance　of　the　antenna　pair　is　matched　by　adjusting　the　element　spacing;　next,　the　EM　input　impedance　is　matched　by　adding　a　coupled　TEM　transmission　line.　Those　two　steps　are　independent　and　easy　to　implement.　Notably,　the　use　of　a　nondispersive　coupled　transmission　line　facilitates　wideband　decoupling　and　intrinsically　allows　an　extremely　small　feed-point　spacing.　The　proposed　antenna　pair　is　experimentally　tested:　it　offers　isolation　higher　than　20　dB　and　total　efficiency　higher　than　87%　from　3.7　to　7.3　GHz　(a　fractional　bandwidth　of　65.5%).　The　separation　between　the　two　feed　points　is　only　5.6　mm　(　$0.069~\lambda　$　at　3.7　GHz).　Furthermore,　we　construct　a　four-element　multiple-input-multiple-output　(MIMO)　array　by　intersecting　orthogonally　two　of　the　proposed　antenna　pairs　at　their　central　line,　which　offer　an　isolation　level　better　than　20　dB　from　3.8　to　7.4　GHz　for　every　two　ports.　With　a　straightforward　design　process,　compact　feeding　structures,　and　wideband　performances,　the　proposed　dual-　and　four-element　MIMO　antennas　are　promising　for　the　fifth-generation　wireless　communication.　©　1963-2012　IEEE.