N092-102 TITLE: Broadband, lightweight, low profile passive phased array

TECHNOLOGY AREAS: Air Platform, Sensors

ACQUISITION PROGRAM: PMA 290 Multi Mission Aircraft

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), which controls the export and import of defense-related material and services. Offerors must disclose any proposed use of foreign nationals, their country of origin, and what tasks each would accomplish in the statement of work in accordance with section 3.5.b.(7) of the solicitation.

OBJECTIVE: Design and develop a single, broadband, lightweight, low profile passive phased array antenna capable of operating across an ultra-wide frequency band to meet requirements listed below for manned and unmanned air vehicle applications. The technology needs to show innovation in research and design with improvement in the following categories over currently fielded designs: weight, depth, aperture efficiency and response linearity.

DESCRIPTION: Current passive, phased array antennas are heavy, bulky and often exhibit poor aperture efficiency and response linearity when attempting to design them to cover large RF bandwidths. Innovative, passive phased array antennas need to be developed that possess improved physical profile / performance characteristics to support multiple USN developmental programs.

The following are design goals for the passive phased array antenna:
-- Frequency coverage: 350 MHz to 6 GHz
-- Gain: Nominally 25 dBil with less than 8 dB of absolute gain ripple and gain variance in performance across the frequency band with some degradation in absolute gain levels expected at the lower frequencies.
-- Polarization: Two orthogonal polarizations +/- 45 degrees desired, with selectable and summed outputs. Polarization responses should track each other within 3dB across the required frequency band.
-- RF outputs: 8 (eight) independent and phase matched RF outputs per polarization (a total of 16) from the antenna are desired
-- Degrees of freedom: Be capable of driving a minimum of 7 nulls while maintaining gain in a commanded direction when the antenna outputs are processed via algorithms such as MUSIC.
-- Beamforming: Static, beamformed, Field of Views (FOVs) on the order of 10 degrees across the spectral range are desired. Performance degradation is permitted somewhat at the lower frequency ranges according to the required physical dimensions.
-- Sidelobe, backlobe and grating lobes: Non-mainbeam lobes suppression of at least -15dB of the main lobe gain while the mainbeam is steered to any position within its Field of Regard (FOR) is desired
-- FOR: +/- 60 degrees from boresight in the horizontal plane
-- FOV: +/- 20 degrees from boresight in the vertical plane
-- Maximum Physical dimensions: 16"x 76"x 3"
-- Total weight: < 40 pounds
-- Electrical characteristics: 50 ohms impedance, VSWR < 2.0:1
The design must be compatible with mounting on surface and airborne assets.

PHASE I: Demonstrate proof-of-concept aperture design using either computer modeling and/or fabrication of a prototype array with limited measured data.

PHASE II: Develop, fabricate and demonstrate prototype (laboratory model) array to design goals. If prototype was developed in Phase 1, further maturation of the design is expected. In either case, performance is to be demonstrated in range and/or chamber testing. Develop electronics to allow beamforming/steering with array.

PHASE III: Transition developed antenna technology to the fleet via airborne integration, operation, performance evaluation testing.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Technology developed under this effort will have potential applications to commercial manned and unmanned air/surface/sea vehicles, and multi-mission aircraft where light, low-profile, high bandwidth antennas are required.

REFERENCES:
1. J. L. Volakis (ed.), Antenna Engineering Handbook, 4th Ed., Chap. 24, J. J. Lee, "Ultra Wideband Arrays", (New York: McGraw-Hill. 2007).

2. C. A. Balanis (ed.), Modern Antenna Handbook, 1st Ed., Chap. 12, W. F. Croswell, T. Durham, M. Jones, D. Schaubert, P. Friederich and J. G. Maloney, "Wideband Arrays", (John Wiley and Sons, Inc., 2008).

3. R. J. Mailloux, Phased Array Antenna Handbook, Boston: Artech House, 1994.

KEYWORDS: Wideband antenna; passive; beam forming; null suppression; beam steering; array

** TOPIC AUTHOR (TPOC) **

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