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 expert in wideband radiator and lens design, proposes a compact, low-loss, conformal Gradient Index (GRIN) lens in the K-band based on additive manufacturing (AM). 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 Phase I our team demonstrated the constraints associated with doped resin approaches to achieving dielectric constants considerably above 3. Several alternatives were demonstrated and an alternative AM approach was baselined which enables the use of very robust, high temperature capable materials in the AM fabrication process. Additionally, these materials provide very low dielectric loss tangents essential to high power applications. 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. During the base period the ARS team will develop the new Additive Manufacturing method demonstrating the approach utility first with lower temperature materials. Later in the base period, the process involving high temperature materials will be implemented and demonstrated. At each milestone, a range of dielectric samples will be produced and characterized to quantify the dielectric properties (value, loss tangent and precision). Following sample production, canonical lens designs will be designed, fabricated and tested to demonstrate the RF performance of the assemblies produced. By the end of the Base period, a high temperature AM process will have been developed and demonstrated capable of producing parts able to support common airborne extreme environments. A parallel effort is planned during the base period that will focus on developing the theory and design process for wide scanning, wideband GRIN Lens antennas. The objective is to develop designs capable of conformal integration with small (Group 1 and 2) size Unmanned Aerial Systems (UAS). As the theory and process mature, example lenses will be fabricated and tested throughout the AM development in the Base period of performance. The proposed Option period objective is to produce a prototype that is capable of flight demonstration. The prototype will be designed, fabricated and extensively tested. A demonstration approach will be developed with stakeholders and supported. The conformal GRIN lens theory and design process will continue to be matured as well as early development of wideband feed antennas.