Air force 14. 1 Small Business Innovation Research (sbir) Proposal Submission Instructions

REFERENCES:

1. F. Bruccoleri, E.A.M. Klumperink, and B. Nauta, “Wide-band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling,” IEEE Journal of Solid-State Circuits, Vol. 39, pp. 275-282, Feb. 2004.

2. S. Blaakmeer, E. Klumperink, D. Leenaerts, and B. Nauta, “Wide-Band Balun-lna with Simultaneous Output Balancing, Noise-Canceling and Distortion-Canceling,” IEEE Journal of Solid-State Circuits, Vol. 43, pp. 1341-50, June 2008.
3. M.T. Reiha and J.R. Long, “A 1.2 V Reactive-Feedback 3.1-10.6GHz Low-Noise Amplifier in 0.13 µM CMOS,” IEEE Journal of Solid-State Circuits, Vol. 42, pp. 1023-1033, May 2007.
KEYWORDS: low noise amplifier, thermal noise, signal processing, low-noise optimization, extremely high frequency, EHF, satellite, noise cancellation

AF141-195 TITLE: Characterization of Atmospheric Turbulence for Long Range Active Electro-Optic

Sensors
KEY TECHNOLOGY AREA(S): Sensors

OBJECTIVE: Develop methods and devices to characterize atmospheric turbulence and its effects on the performance of long-range active electro-optical sensors.

DESCRIPTION: Atmospheric optical turbulence can have deleterious effects on the data quality of active sensors. Most current turbulence measurement systems give path integrated turbulence metrics (for example, atmospheric coherence diameter). Some systems are able to characterize the atmosphere at intermediate points along a path but are not well suited to a dynamic flight environment. Active coherent laser sensors operating near the earth are more sensitive to atmospheric turbulence than passive non-coherent imaging due to the cumulative effects of variations of piston, and their sensitivity to changes of the measured phase. A full understanding of atmospheric optical turbulence, its spatial and temporal coherence attributes and their effects on coherent laser radar systems (e.g., scintillation, beam wander, beam breakup, etc.) is desired to improve the performance of current and future intelligence, surveillance, and reconnaissance (ISR) optical systems and their models. Without an in-situ measurement of the turbulence experienced by these sensors, understanding their performance is difficult. Characterization parameters measured in flight and along the line of sight to the target include but are not limited to: refractive index structure function parameter, Rytov number, atmospheric coherence width, iso-planatic patch size, turbulence assessment at various locations along the path, aero-optic characterizations, and pertinent weather variables (temperature, humidity and their gradients, pressure, wind, etc.). Systems capable of measuring these atmospheric parameters from both ground and airborne locations and at ranges of many tens of kilometers are desired.
Information gained by the development of atmospheric turbulence devices will be used to develop highly detailed physics-based models of the atmosphere, its effects on active imaging, and ways to mitigate the effects both in hardware and software. Knowing the underlying causes of image degradation due to atmosphere activity could then be used to extrapolate and predict performance in other types of atmospheres (for example, Mid-Atlantic, desert, arctic, etc.)
This topic seeks to develop atmospheric characterization techniques to determine the amount of phase errors introduced and their spatial and temporal correlations. Techniques for mitigation of the atmospheric phase may require knowledge of the atmosphere for benchmarking of mitigation techniques and sensor characterization.

PHASE I: Plan, analyze, and design systems capable of characterizing and assessing atmospheric optical turbulence and its effect on the performance of coherent ladar systems in air-to-air, air-to-ground, and ground-to-ground scenarios.

PHASE II: Develop prototype system (employing the design of Phase I) to measure required parameters to properly characterize atmospheric turbulence in air-to-air, air-to-ground, and ground-to-ground scenarios. Minimizing the technology as small as possible is desired. Airborne demonstrations are preferred but ground-based demonstrations are acceptable. This technology has non-military applications: NASA space observations and imaging, NOAA earth imaging, and data for adaptive optics applications.

PHASE III DUAL USE APPLICATIONS: The end-products of this solicitation will be applicable to many of the laser-based systems under development by the Air Force Research Laboratory and across the Department of Defense. Commercial applications include wind/turbulence sensing for commercial airports' landing advisories.

REFERENCES:

1. Andrews, L. C., & Phillips, R. L. (2005). Laser Beam Propagation Through Random Media (2nd ed.). Bellingham, WA: SPIE.

2. Doviak, R. J., & Zrnic, D. S. (2006). Measurements of Turbulence and Observations of Fair Weather. Doppler Radar and Weather Observations (2nd ed., pp. 386-505). Mineola, NY: Dover Publications.
3. Karr, T. J. (2003). Resolution of Synthetic-Aperture Imaging Through Turbulence. JOSA-A, 1067-1083.
4. Karr, T. J. (2007). Atmospheric Phase Error in Coherent Laser Radar. IEEE Transactions on Antennas and Propagation, pp. 1122-1133.
5. Frehlich, R. G., & Kavaya, M. J. (1991). Coherent Laser Radar Performance for General Atmospheric Refractive Turbulence. Applied Optics, pp. 5325-5352.
KEYWORDS: turbulence, optical turbulence, index of refraction structure function, scintillometer, synthetic aperture ladar
AF141-196 TITLE: Hybridization Techniques for Ultra-Small Pitch Focal Plane Arrays
KEY TECHNOLOGY AREA(S): Sensors
The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Kristina Croake, kristina.croake@us.af.mil.

OBJECTIVE: Design, develop, and demonstrate high yield, reliable, reproducible, and affordable hybridization techniques for ultra-small (< 5 µm) pitch infrared focal plane arrays (IRFPAs).

DESCRIPTION: At the heart of virtually every infrared (IR) imaging system there is a sensor (the focal plane array) that detects and converts the incoming infrared radiation into an electrical signal in order to form an image. This focal plane array (FPA) is comprised of two components, the detector array and the readout integrated circuit. The detector array is the infrared-sensing part of the sensor and can be made from a wide variety of materials that are sensitive in the wavelength band of interest. The readout integrated circuit (ROIC) is the signal processing component and is generally fabricated on a silicon substrate using volume production integrated circuit processes. Once each component is fabricated and functionality is verified, they are mated physically and electrically through an indium bump hybridization process to form a focal plane array.
Persistent surveillance IR imaging systems are in wide use within the U.S. Air Force. These systems are incorporated into a wide variety of aircraft, from unmanned aerial vehicles at low altitudes to satellites that operate in space. These systems typically employ staring FPA technology, sometimes up to multi-megapixel geometries. They allow for wide area surveillance and are a critical tool for our warfighters. Through the years, there has been a push towards higher resolution in order to resolve smaller features at higher altitudes. In order to maintain the aperture size of the existing optics with increased resolution, the only option is to decrease the existing detector pixel spacing (pitch). Current indium bump bond technology is used on both the ROIC and detector array assemblies down to a pitch of around 12 µm with almost 100 percent yield.
There is a need to establish a FPA hybridization concept that allows for high yield, reliable, reproducible, and affordable interconnects for < 5 µm pitch IRFPAs. Pushing the pitch to this level is a huge challenge since the ROIC and detector arrays are seldom made of the same material, meaning that they may have vastly different coefficients of thermal expansion. In addition, the detector array may have issues such as wafer bow, variations in total thickness, and can be made of materials that are soft, delicate, or difficult to handle.
Innovative hybridization approaches to achieve < 5 µm square pixel pitches using a silicon ROIC mated to a variety of detector materials (to include HgCdTe, GaAs, GaSb, and InSb at a minimum) are being sought. Z-technologies with multi-level interconnects are being pursued elsewhere and will not be considered under this topic. Candidate methods shall be thoroughly characterized to determine overall interconnect yield and shall undergo a series of temperature cycling (300K to 77K) and other reliability tests to determine the effect on interconnect yield.

PHASE I: The contractor will conduct a study of detector materials to determine material properties in comparison to silicon ROICs. The contractor will then develop appropriate candidate approaches that can be used with a variety of detector materials using techniques that are compatible with standard IRFPA processing methods. A small scale test chip shall be demonstrated at the conclusion of Phase I.

PHASE II: Using the designs developed in Phase I (with optimization), the contractor will design, fabricate, and demonstrate multi-megapixel FPA test chips that employ a variety of detector material test chips (to include HgCdTe, GaAs, GaSb, and InSb at a minimum) that are hybridized to dummy silicon ROIC chips. These hybrid arrays will then be characterized for interconnect yield and will then be subjected to a series of reliability tests in order to determine the integrity of the < 5 µm interconnects.

PHASE III DUAL USE APPLICATIONS: The contractor will team with an FPA producer to demonstrate this technique on an operational FPA. Comparisons between this and standard methods will be carried out. This technology will be applicable to a variety of applications requiring high density, small pitch, reliable interconnects.

REFERENCES:

1. John, J. et al., "High-Density Hybrid Interconnect Methodologies," Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 531, Issues 1–2, (2004), p. 202.

AF141-197 TITLE: Novel Signal Processing for Airborne Passive Synthetic Aperture Radar

OBJECTIVE: Develop innovative techniques and algorithms for airborne passive synthetic aperture radar (SAR) imaging using terrestrial commercial transmitters as sources-of-opportunity.

PHASE I: Define performance metrics for high-resolution airborne passive SAR imaging. Conduct a trade study to select a set of illuminators to exploit for the effort. Develop innovative image formation algorithms and techniques tailored to the selected illumination sources. Validate the proposed imaging scheme through simulation.

PHASE II: Mature the techniques developed in Phase I to support operation across multiple bands and multiple transmitters. Address practical implementation concerns including autofocus, direct path cancellation, and other potential challenges identified during Phase I. Demonstrate and validate the developed techniques on either measured or high-fidelity simulated data.

PHASE III DUAL USE APPLICATIONS: Transition opportunities for this effort include ongoing passive radar efforts at AFRL and other government labs as well as UAV and aircraft program offices. Potential commercial applications include law enforcement and low-cost SAR mapping.

REFERENCES:

1. IEEE Aerospace and Electronic Systems Magazine, Volume 27, Issues 10-11, 2012.

AF141-198 TITLE: Aperture Synthesis for Partially Coherent and Passive Illumination

OBJECTIVE: Develop electro-optic (EO) infrared (IR) sensors using aperture synthesis for partially coherent and passive illumination, providing increased resolution with reduced sensor volume and speckle noise.

PHASE I: Investigate innovative approaches and model performance for potential airborne applications. All key aspects to the imaging functionality should be modeled to determine signal to noise ratio (SNR), turbulence, exposure time, and detector noise that enable successful aperture synthesis. Foundational experiments to verify theoretical concepts should also be conducted.

PHASE II: Mature design and develop brassboard demonstrations for aperture synthesis techniques. Design shall include requirements for all key subsystems, such as sensor array, laser transmitter, and receiver optics. Brassboard demonstrations should verify functionality in turbulent atmospheres and confirm models used to determine system requirements.

PHASE III DUAL USE APPLICATIONS: Develop hardware suitable for integration in an airborne platform and demonstrate ability to perform synthesis in relevant atmosphere for large fields of view. Dual-use applications include commercial imaging and surveillance for ground-, air-, and space-based systems.

REFERENCES:

1. Bertero, M. et al, “Imaging with LINC-NIRVANA, the Fizeau Interferometer of the Large Binocular Telescope: State of the Art and Open Problems,” Inverse Problems, Vol. 27, (2011).