Miniaturized antenna arrays using decoupling networks with realistic elements

In ordinary antenna arrays, the spacing between radiators is usually chosen lambda/2. In order to use antenna arrays in small mobile platforms, the overall dimensions and, hence, the radiator separation, must be reduced, which aggravates the problem of mutual coupling between radiators. Results are highly distorted beam patterns and greatly reduced radiation efficiency. We propose a method to design a decoupling and matching network for a three-element antenna array with a radiator separation of lambda/10, which additionally allows arbitrary beam patterns assigned to each port-subject to certain constraints. An iterative process is employed to account for network losses, which are unavoidable in any realistic network implementation