High-efficiency super-gain antenna arrays

It is an intriguing fact that the array gain of densely packed antenna arrays can be much larger than the number of antennas which comprise the antenna array. However, their large array gain seems to be inaccessible in practice, for it tends to be all eaten up by a loss of effciency that accompanies such super-gain effects. In this paper, the authors argue that the assertion given above is based on a less than optimum choice of antenna separation inside the array as well as on less than optimum antenna excitation currents. We demonstrate that if both those issues are addressed optimally super-gain actually can be obtained with high effciency. Compact antenna arrays therefore deserve to be given more attention in both the antenna-, and the signal processing layers of abstraction, for the successful application of such arrays requires optimum design in both layers.