Design and Optimization of Multiport Pixel Antennas

We describe a method for the design and optimization of multiport pixel antennas for application in multiple-input multiple-output (MIMO) communication systems. A rectangular grid of pixels with connections between them is used as a design surface for multiport antenna design. Genetic algorithm optimization is used to find the optimal configuration of connections between pixels and multiple input port locations under the constraints of high isolation between all ports and good impedance matching for all ports over the desired frequency band and/or beam direction. The method utilizes a scalar single-objective function that takes account of return loss, isolation between ports, and antenna gain, and makes use of the internal multiport method. Examples of MIMO antenna optimization for a 2-port MIMO dual-band antenna operating at 2.4 and 5 GHz without pattern optimization and an example for a 2-port MIMO single-band antenna operating at 5 GHz with pattern optimization (forming orthogonal endure main beams) are provided.