Modeling Mutual Coupling in Large Arrays Using Embedded Element Pattern
This example demonstrates the embedded element pattern approach to model large finite arrays. Such an approach is only good for very large arrays so that the edge effects may be ignored. It is common to consider an infinite array analysis as a first step for such kind of analysis. This approach is presented in ; Modeling Mutual Coupling in Large Arrays Using Infinite Array Analysis>. The embedded element pattern refers to the pattern of a single element embedded in the finite array, that is calculated by driving the central element in the array and terminating all other elements into a reference impedance -. The pattern of the driven element, referred to as the embedded element, incorporates the effect of coupling with the neighboring elements. It is common to choose the central region/element of the array for the embedded element, depending on whether the array has an even or odd number of elements(for large arrays it does not matter). The pattern of the isolated element (the radiator located in space by itself) changes when it is placed in an array due to the presence of mutual coupling. This invalidates the use of pattern multiplication, which assumes that all elements have the same pattern. To use pattern multiplication to calculate the total array radiation pattern, and improve the fidelity of the analysis, we replace the isolated element pattern with the embedded element pattern.