Antenna designs for MIMO systems by the pixelated design technique

For the past decade, antenna designs for MIMO systems rely more and more on tuning the geometric parameters of an initial layout. For instance, if the design goal is to generate double resonances in dual bands and reduce the mutual coupling between multiple antenna elements, a planar-inverted F antenna is typically considered as the design prototype along with a predetermined decoupling technique; afterward, the geometric parameters of the prototype are identified and fine tuned via either a trial-and-error approach or traditional shapeoptimization methods. However, such approaches may fail to produce a satisfactory design if the detailed initial guess is incorrect; moreover, fine tuning continuous variables is a repetitive and tedious task, which expands the designcycle and increases development cost.