Additive Manufactured Low-Loss Small-Size Low-Profile Conformal GRIN Lens in the K-Band

Agile RF Systems (ARS), in conjunction with University of Oklahoma experts in wideband radiator and lens design (Dr. Jorge Salazar-Cerreno) and additive manufacturing using nano-particles (Dr. Joseph Tischler), proposes a compact, low-loss, conformal GRIN lens in the K-band based on additive manufacturing (AM) with novel composite ceramic materials. Compact planar lenses generally require a high dielectric constant gradient, with the central lens portion having a relative dielectric constant around 10. In practice, the designer is often limited by the dielectric constants of standard AM materials, which generally hover around 3. In order to take advantage of the fabrication benefits of additive manufacturing, the ARS team proposes doping standard 3D printed materials with a SrTiO3 nano-powder to produce a printable material with a relative dielectric constant of up to 20. Strontium titanate has a loss tangent less than 0.003, so it will not notably increase ohmic losses. Critically, additive manufacturing with this doped material allows for a nearly-continuous dielectric constant gradient in all three spatial dimensions. This is in contrast to the typical stacked approach which often has minimal vertical spatial gradient or has discrete layers, which can prevent wideband impedance matching and increase sidelobes. The proposed system is volumetrically compact, lightweight, low-loss, able to be conformally mounted to an aircraft, and can achieve wide-angle scanning with reduced sidelobes relative to comparable approaches.