Multifunction antennas - the interleaved sparse sub-arrays approach

A solution to designing multifunction array antennas is discussed. Distinct system functions performed at separate frequency ranges are associated to sparse sub-arrays that are interleaved in a shared aperture configuration. The sparse architectures are designed using a combinatorial method that ensures an acceptable behavior in the side-lobes region in conjunction with a narrow beamwidth. Experimental and numerical results are presented for a shared aperture antenna consisting of two interwoven sub-arrays that jointly cover a fractional bandwidth of 14% in the X-band