TECH FOCUS AREAS: General Warfighting Requirements (GWR) TECHNOLOGY AREAS: Sensors; Electronics; Materials OBJECTIVE: Fabrication of a first generation 32 element radar receiver that images for multi-static and bi-static applications with added functionality as a Signals Intelligence (SIGINT) and communication receiver if feasible within the program. The backend should be software defined and library loaded if in radar warning receiver (RWR) mode, with as large a beam bandwidth possible (within cost constraints, expandable upon enhanced funding and modular to 2-dimensions for further transition) demonstrating maximum bandwidth in at least 1 beam. Multi-static proof of principle demonstrated in laboratory or range, algorithm requirements at least road-mapped if not developed and implemented. Concept of Operations (CONOPS) and scheme. DESCRIPTION: As use of the radio frequency (RF) spectrum by both red and blue forces continues to expand both to higher frequencies and in producing higher signal density of the environment, the next generation of communications and radar receiver systems will need more capability to route and process signals, and conventional electronic processors will struggle with the data flow especially if receivers are tasked with multiple missions in dense threat environments. Systems have been demonstrated using RF photonic techniques that provide real-time analog spatial and spectral processing of these high frequency signals within dense signal environments. Sorting of signals by analog imaging provides tremendous benefits including instantaneous direction finding and/or carrier frequency information, the relieving of the processors of beamforming thereby freeing up significant digital bandwidth so that processors can function solely as waveform analyzers. New generations of digitizers make extremely wideband receivers possible, putting even more emphasis on analog beam processing as a way to unburden already overstrained data pipelines. These new digitizers offer up to about 35GHz per beam instantaneous bandwidth, giving a huge potential >1TB/s beam-bandwidth product on a 1x32 receiver for instance, and sending that digital data flow to backend processors. Data bottlenecks would remain; however, the problem is no longer bottlenecked at the same locations and by having data sorted by beam direction at least processors canst threat directions if the instantaneous bandwidth needs to be large. Radar warning receivers in dense environments will probably also have to double as SIGINT receivers in order to deal with the large number of signals and more constrained Size, Weight, and Power (SWaP) environments on today's platforms. RF analog imaging offers avenues for this as again the backend digitizers may feed the same processors, but programmed for a different mission, or even multi-missions. This software defined backend, combined with analog beamforming, will in turn enable a much more agile and capable RF mission set on one phased array. RF Analog imaging is also an enabling technology for future multi-static radar systems as radar returns can come from anywhere in the field of view at any time, making wideband analog imaging extremely useful in that regard. Multi-static radar offers tremendous promise for future warfighting as large emitting radar platforms are increasingly becoming obsolete in high threat environments as expendable low-cost transmitters may be flown in forward of high value receivers. Multiple transmitters illuminate the forward area and therefore a staring imaging receiver is an attractive option for receiving the returns as there may be multiple signals at random directions and time delays. In the past, photonics has offered a way to perform this imaging by modulating received electronic signals onto optical carriers. This conversion is accomplished by means of an electro-optic modulator and the RF signals have been collected within a phased array and then imaged onto high data rate phototransistors. This generation of system can take advantage of advancements in the modulators recently. PHASE I: This topic is intended for technology proven ready to move directly to Phase II. Therefore, a Phase I award is not required. The offeror is required to provide detail and documentation in the Direct to Phase II proposal which demonstrates accomplishment of a Phase I-like effort, including a feasibility study. This includes determining, insofar as possible, the scientific and technical merit and feasibility of ideas appearing to have commercial potential. PHASE II: Eligibility for D2P2 is predicated on the offeror having performed a Phase I-like effort predominantly separate from the SBIR Programs. Under the Phase II effort, the offeror shall sufficiently develop the technical approach, product, or process in order to conduct a small number of advanced manufacturing and/or sustainment relevant demonstrations. Identification of manufacturing/production issues and or business model modifications required to further improve product or process relevance to improved sustainment costs, availability, or safety, should be documented. Air Force sustainment stakeholder engagement is paramount to successful validation of the technical approach. These Phase II awards are intended to provide a path to commercialization, not the final step for the proposed solution. PHASE III DUAL USE APPLICATIONS: The contractor will pursue commercialization of the various technologies developed in Phase II for transitioning expanded mission capability to a broad range of potential government and civilian users and alternate mission applications. Direct access with end users and government customers will be provided with opportunities to receive Phase III awards for providing the government additional research & development, or direct procurement of products and services developed in coordination with the program. REFERENCES: 1. C. A. Schuetz et al., A Promising Outlook for Imaging Radar Imaging Flash Radar Realized Using Photonic Spatial Beam Processing, IEEE Microwave Magazine, vol. 19, no. 3, pp. 91 101, May 2018, doi: 10.1109/MMM.2018.2801639. KEYWORDS: First generation 32 element radar receiver; multi-static and bi-static; SIGINT and communication receiver; radar warning receiver (RWR) mode; large a beam bandwidth; Multi-static proof of principle
