Patent ID: 8463222

Claim:
A multiple-input multiple-output (MIMO) antenna device adapted for connecting electrically to a radio frequency (RF) circuit so as to transmit and receive RF signals, said MIMO antenna device comprising: a circuit board having a peripheral edge; a number (N) of antenna units disposed on said circuit board proximate to said peripheral edge of said circuit board and arranged in a loop formation, wherein the number (N) is a positive integer; a (1×M)-multiplexer unit disposed on said circuit board, connected electrically to a number (M) of corresponding ones of said (N) antenna units, and operable to select one of said (M) corresponding ones of said antenna units for connecting electrically the selected one of said antenna units to the RF circuit, wherein the number (M) is a positive integer; and a (1×(N−M))-multiplexer unit disposed on said circuit board, connected electrically to remaining (N−M) corresponding ones of said (N) antenna units, and operable to select one of said (N−M) corresponding ones of said antenna units for connecting electrically the selected one of said antenna units to the RF circuit; wherein said circuit board has a ground plane, and said (N) antenna units are disposed to surround said ground plane.