Fig 1.
Geometry of Design-1 and Design-2.
The optimized values of Design-2 are as follows: w = 8.4, g = 1.4, ls = 11.2, ws = 1.3, wf = 1.5, s = 3.0 (unit: mm).
Fig 2.
Simulated |S11| of Design-1 and Design-2.
Fig 3.
Geometry of different 2-port adjacent MIMO antennas.
Fig 4.
Simulated |S11| and |S21| of MIMO-1 and MIMO-2 designs.
Fig 5.
Geometry of 2-port opposite MIMO antennas with shorting pins.
Fig 6.
Simulated |S11| and |S21| of MIMO-3 with and without shorting pins.
Fig 7.
Simulated |S11| and |S21| of MIMO-3 with different shorting pin position, d.
Fig 8.
Simulated current distributions on the ground with and without shorting pins.
Fig 9.
Geometry of different 4-port MIMO antennas.
Fig 10.
Simulated S-parameter of MIMO-4.
Fig 11.
Simulated 3-D radiation pattern of MIMO-4.
Fig 12.
Simulated S-parameter of MIMO-5.
Fig 13.
Simulated 3-D radiation pattern of MIMO-5.
Fig 14.
Simulated S-parameter and 3-D radiation pattern of MIMO-6.
Fig 15.
Calculated ECC values of the proposed 4-port MIMO antenna, MIMO-6.
Fig 16.
Simulated current distribution on the final MIMO antenna, MIMO-6.
Fig 17.
Photographs of fabricated 4-port MIMO antenna.
Fig 18.
Measured S-parameter of the proposed 4-port MIMO antenna.
Fig 19.
Simulated and measured broadside gain of the proposed 4-port MIMO antenna.
Fig 20.
Simulated and measured radiation patterns of the proposed 4-port MIMO antenna with Port-1 excitation.
Table 1.
Performance comparison among low-profile wideband MIMO antennas.