Additively Manufactured Conformal Feeds for Passive Beamforming

Designing low cost, broadband and wide scan angle beamforming systems is critical for a diverse range of commercial and military applications. Many current beamforming approaches either involve complex phased arrays or large mechanically steered antennas. The phased arrays are often prohibitively expensive while the mechanically steered systems are often too slow, heavy, and susceptible to mechanical failures. An alternative approach involves the use of graded index (GRIN) RF lenses as passive beamformers. Recently the reliable fabrication of RF GRIN lenses is made possible with the use of advanced additive manufacturing (AM) systems and materials. Through AM, GRIN based RF lenses have recently been reported that possess high radiation efficiencies, high antenna gains, and ultra-wideband operations [1] . Current GRIN devices, while greatly improved, still often lack the wide-angle steering and efficient conformal feed structures needed for some of the more challenging applications. In this presentation, we describe the design and fabrication, via additive manufacturing, of an array of conformal feeds. When integrated with a graded index beamforming lens, such as the Luneburg lens or modified versions, results in an ultra-wide scan angle beam steering device. Specifically, we will describe the design and fabrication, via AM, of an integrated beam steering device that combines: (1) printed conformal RF connectors, (2) printed broadband baluns, (3) printed broadband feed antennas, and (4) a novel GRIN lens.