Practical two-dimensional antenna arrays for high-latitude over-the-horizon radar systems

A model for two-dimensional antenna arrays is presented that accounts for mutual coupling between elements. The model is used in an over-the-horizon radar application, where the elevation resolution of the array permits the user to separate target echoes from clutter originating in the aurora borealis. The impact of the mutual coupling reduces the achievable improvement in signal-to-clutter ratio. In the case of the transmit array, the effects of mutual coupling can be overcome by applying the appropriate amplitude and phase corrections to each transmit channel. In the case of the receive array, it is adequate to boost the input impedance of the receivers to overcome the mutual coupling.