Integration of an X-band microstrip patch array and beamformer for a multifunction antenna array

Light-weight phased array antennas for aerospace applications require utilizing the same antenna aperture to provide multiple functions with dissimilar radiation pattern specifications (e.g., multi-band operation for communications and tracking). Multi-functional antennas provide advantages over aggregate antenna clusters by reducing space requirements, and can aid in the optimal placement of all required apertures to provide adequate isolation between channels. To achieve needed isolation between antenna bands when multiple radiators are in close proximity requires proper selection of antenna topology and the feed network design. This paper seeks to highlight design challenges in the implementation of an X-band (12 GHz) microstrip patch array into a superstrate layer covering printed dual-band slot loop antennas. We describe a novel feature in the proposed design wherein the high frequency array conforms to a specific topology allowed by lower frequency elements to create a single multi-band, multi-functional aperture.