Multi-objective optimization design of compact MIMO antennas with canonical structures (viz., transformation or combination by regular shapes) for wideband radiation and fragment structures (viz., combination by discrete fragment patches) for high isolation is proposed and demonstrated. In the design, MOEA/D-DE for optimization of canonical structures and MOEA/D-GO for optimization of fragment structures are combined and iterated. The design is demonstrated with compact bow-tie MIMO antennas sharing a small common ground plane. The four orthogonally deployed bow-tie antennas are optimized by using MOEA/D-DE to acquire dual polarization and wideband radiation. Fragment-type structures on the common ground plane are optimized by using MOEA/D-GO to acquire very high isolation. Both simulation and measurement show that the optimized MIMO bow-tie antennas provide isolation higher than 30dB in a relative bandwidth of 4o% (from 2.6GHz to 3.9GHz). With the proposed design technique, dual-band high isolation MIMO antennas may also be designed.
- wideband antennas