Multi-band adaptive array antenna by means of switched parasitic elements

A multi-band adaptive array antenna has been proposed. The aperture is consisted by a central radiating element and several parasitic elements on the counterpoise. Multi-band monopole is applied to the central radiating element. The parasitic elements are located on various concentric circles of which radius is proportional to the wavelength. Output of the parasitic element is connected to either the open circuit or a switched load. When the parasitic elements on a circular array corresponding to the desired frequency are used, each switched load is set such that the correlation between symbols received by the central element and the reference is maximized by means of the Full Search Method. Monte-Carlo simulation shows probability that the correlation coefficient exceeds 0.99 in case of 2 incident signal is 0.92 and that the unused array has little influence. VEGA can be used in order to optimize the correlation coefficients and VSWR at the same time.

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