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A -- PART 1 OF 2. ADVANCED ANTENNA SYSTEM ARCHITECTURES SOL N66001-96-X-6902 DUE 061397 POC Contracting Officer, Ed Brown, (619)553-5725. Broad Agency Announcement (BAA). The Naval Command, Control and Ocean Surveillance Center (NCCOSC), RDT&E Division's (NRaD) Electromagnetics and Advanced Technology Division is conducting research and development efforts for advanced antenna system architectures and technologies for current and future Naval surface combatants. Many current shipboard antennas, particularly those required for satellite coverage, are highly directional and require precise steering with heavy, expensive pedestals. The negative result is that they are expensive, add weight aloft compromising ship stability, and add large radar reflecting surfaces, which will dominate the Radar Cross Section (RCS) of future low signature surface combatants. The objective of this BAA is to develop technology for mitigating these effects of shipboard satellite communications (SATCOM) antennas. Emphasis is on the capability of a multi-beam, multi-band SATCOM antenna aperture in a low observable shipboard structure with reduced infrared (IR) signature and radar cross section (RCS). Ultra-high frequency (UHF) SATCOM (240 - 318 MHz), International Maritime Satellite (INMARSAT)(1.535 - 1.5425 GHz down, 1.6365 - 1.644 GHz up), extremely high frequency (EHF) SATCOM (44 GHz, up; 20 GHz down) and Global Broadcast System (GBS; 20 GHz down) are candidates for the proposed antenna system. The antenna system would emphasize a fully integrated multi-beam, multi-band antenna aperture that can be fielded in a shipboard demonstration within technology and cost considerations. Affordability is recognized as a principal area of risk. The antenna design would meet existing satellite communication signal, gain, and sensitivity requirements in a planar architecture while achieving seamless array-face to array-face hand-off during satellite capture periods. A goal of this effort is to leverage to the greatest extent possible commercial off-the-shelf (COTS), non-developmental items (NDI) and related Department of Defense efforts in the development and demonstration of low signature, multi-beam, multi-band SATCOM antennas. Two phases are being considered. Phase 1 would focus on detailed design and design demonstrations (e.g., the building of sub-arrays). Phase 1 would thus reduce the risk associated with developing full-scale demonstrations of the low signature, multi-beam, multi-band SATCOM antenna. In addition, Phase 1 would establish the performance and cost of producing full demonstration models. Phase 2 would develop the full-scale demonstration models as well as cost estimates for future production versions of the antennas. At this time it is envisioned that the Phase 2 antennas would be demonstrated within the context of the FY98 Low Observable, Multi-function Stack (LO Stack) Advanced Technology Demonstration (ATD). The following describes the Navy's concept for the configuration of the Shipboard Low Observable Multi-band, Multi-beam SATCOM antenna: The antennas will be embedded in a composite structure that is mounted conformally into a low signature composite ship superstructure surface.--The antenna apertures will consist of two-dimensional phased arrays which are electronically steerable to provide hemispherical coverage. This is envisioned to reduce shipboard maintenance requirements--The ship superstructure will likely consist of four orthogonal flat surfaces that are tilted 10 to 15 degrees from the vertical to form a pyramidal shape. The top of the pyramid may not be available for antenna components. The exact configuration and slope of the superstructure surface will be a trade-off of antenna performance, signature, and topside arrangements requirements.--The UHF and INMARSAT apertures will both be full-duplex, and the INMARSAT aperture will be nested within the physical confines of the UHF aperture. A goal is to minimize the physical size of this aperture.--The EHF transmit function will be achieved by a separate aperture--The EHF Receive and GBS Receive functions will use a common aperture.--It is desirable to nest all apertures within a common physical aperture.--The antenna apertures will have IR signature and RCS control built into them. This BAA requests submittals in the following technical areas: 1) EHF SATCOM Transmit Aperture: On-going DoD projects are expected to adequately address the Phase 1 effort for the EHF transmit function and therefore work in this area is not expected to be funded. Submittals discussing potential phase two efforts for EHF SATCOM transmit are encouraged. For the Phase 2 demonstration the minimum performance is that of a 6 inch reflector. 2) Integrated EHF SATCOM Receive and GBS Receive: It is proposed that the GBS and EHF SATCOM receive functions be combined into a common aperture, switchable between the two applications. To support GBS Receive the receive aperture would have as a minimum a G/T of 10.6 dB over a 45 degree scan angle. It is desired for the demonstration model that the scan angle in the horizontal direction be such that four orthogonal apertures cover a 360 degree view and the vertical scan capability provide coverage to zenith. The polarization would be switchable between left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) to support both GBS and EHF SATCOM receive. The Phase 1 effort would be directed toward the development of an electronically steerable sub-array and establish the cost and performance for the Phase 2 demonstration model. 3) Integrated UHF SATCOM and INMARSAT: This area addresses the development of a full-duplex UHF SATCOM antenna and full-duplex INMARSAT antenna integrated into a common aperture. The transmit and receive capabilities of a full set of four orthogonal apertures must be such that the integrated antenna has the same performance as existing shipboard systems over full hemispherical coverage. The Phase 1 task would demonstrate that a fully integrated sub-array can be built with the desired performance. This effort would mitigate risk by establishing the cost required for development of the full-scale demonstration models. Phase 2 would be the development of full-scale demonstration models. 4) Tracking and hand-off: A single tracking and hand-off system is envisioned for the low observable multi-beam, multi-band SATCOM antenna. This system would use a common architecture to provide the necessary control for tracking and hand-off for all of the arrays. A Phase 1 effort might build on one of the sub-array demonstrations and be used to demonstrate the tracking and hand-off. 5) Shipboard Integration: This area is concerned with the integration of the individual antenna apertures into the ship superstructure while meeting the defined signature goals. Integration with the appropriate shipboard electronic systems must also be demonstrated. A Phase 1 task might evaluate trade-offs between different signature control techniques for RCS and IR signatures and their effect on the performance of the low signature, multi-beam, multi-band SATCOM antenna. A Phase 2 effort would extend the results of the trade-offs to the full scale demonstration of the apertures. Resondents having knowledge of these technologies and their applications to Naval shipboard SATCOM antenna design and development are encouraged to originate and submit their ideas for evaluation and potential funding. Offerors are especially invited to submit an initial five page white paper on potential proposed technical efforts within thirty days of the date of this BAA, presenting Phase 1 and/or Phase 2 concepts, the technology area(s) from the five technology areas presented above, technical description of the effort, a preliminary schedule, identification of risks, a rough cost estimate and implications to a phase 2 effort. All technical approaches will be considered. White papers may address one or more technical areas and/or phases, but completeness will be considered due to the interrelationship of the technical areas. Offerors may submit more than one white paper. This BAA will remain open for one year from the date of publication. White papers will be accepted up to one year after BAA publication. However, initial evaluation of white papers and subsequent requests for initial proposals will be based upon those white papers received within the first thirty days after BAA publication. Initial contract award is anticipated for the beginning of the fiscal 1997 (1 December 1996). Submitted white papers will be evaluated as to their potential interest to the Government according to the following criteria: 1) relevance and effectiveness with which the proposed technology and application meets the objective of this shipboard low observable multi-band, multi-beam SATCOM antenna effort, and 2) suitability and adequacy with which the proposed technical approach fits with anticipated needs. Respondents whose white papers are deemed favorable with respect to the above criteria will be invited to submit full proposals within 30 days for further consideration. Proposals must be submitted in two separate volumes, a technical volume and a cost volume. The technical volume is limited to 35 pages (eight and one-half by eleven inches, one inch margins on all sides, 12 point font). The technical volume should include the technical approach and rationale of the proposed effort, schedule and milestones, proposed metrics for gauging technical advances, potential risks, a statement of work (actual tasks that will be performed), description of anticipated results, brief, pertinent resumes of the principal investigator and key personnel, similar work experiences in the proposed area, and a description of the facilities. The technical volume should also list deliverables (monthly progress reports, meeting minutes, review presentation slides, plans, reports, etc.), and the offeror should anticipate hosting a kickoff meeting, quarterly/milestone reviews, and a final review. (0170)

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