Systematic characterization of element coupling in high-directivity antenna arrays

In this contribution, large (high-directivity) antenna arrays are treated as coupled-resonator structures. It is shown that sufficiently high resonator quality factors guarantee single-mode operation of the individual array elements. It is also shown that the traditional tendency to minimize or even eliminate inter-element coupling, which puts severe limitations on the array design and fabrication processes, is not necessarily advantageous in all cases. In addition, a systematic characterization of this coupling is presented and/or revisited, which is applicable to those cases, in which element coupling cannot be neglected. It simplifies the design of steerable high-directivity antenna arrays with large number of elements. It can also be used in error diagnostics (the inverse problem). Only one-dimensional arrays are investigated in this contribution. The generalization to the two-dimensional case is however straightforward.