N131-057 TITLE: Solid-State Modulator Replacement of Tube-based Modulators

TECHNOLOGY AREAS: Sensors

ACQUISITION PROGRAM: PEO IWS 2, Above Water Sensors

RESTRICTION ON PERFORMANCE BY FOREIGN CITIZENS (i.e., those holding non-U.S. Passports): This topic is "ITAR Restricted". The information and materials provided pursuant to or resulting from this topic are restricted under the International Traffic in Arms Regulations (ITAR), 22 CFR Parts 120 - 130, which control the export of defense-related material and services, including the export of sensitive technical data. Foreign Citizens may perform work under an award resulting from this topic only if they hold the "Permanent Resident Card", or are designated as "Protected Individuals" as defined by 8 U.S.C. 1324b(a)(3). If a proposal for this topic contains participation by a foreign citizen who is not in one of the above two categories, the proposal will be rejected.

OBJECTIVE: The object is to develop a solid-state switch modulator for the SPY-1 Radar Cross-Field Amplifier (CFA) Final Power Amplifier (FPA) cabinet.

DESCRIPTION: This topic seeks to replace existing Switch Tubes with state of the art solid-state amplifiers (see references 1-4). The required innovation is to develop solid-state power amplifier circuits to replace current high power Switch Tubes. Current Switch Tubes use vacuum tube technology. Vacuum tubes use high power, and manufacturing resources are diminishing. Final Power Amplifier (FPA) sub-assemblies (Electronic Switch, Electronic Switch Driver, and Electronic Switch Driver Power Supply) use vacuum tube technology and have been identified as three of the top ten failure items. This is a significant contributor to total life-cycle costs of the SPY-1 radar. Vacuum tube technology is being replaced by solid-state technology in government and industry. The Navy is concerned that switch tube amplifiers and other high cost FPA components including switch tube sockets, spark gaps, high power transformers and other FPA-unique electronics used in the FPA are becoming obsolete. The Navy needs to reduce life-cycle costs of the FPA.

The Navy is seeking innovative solid-state solutions to address the costs through delivery of individual Lowest Repairable Units (LRU). A high level of design-for-repair success may include the use of soft potting material, where required, to insulate high voltage components. Optimum design-for-repair may include no potting materials; however, form, fit, function, space and thermal constraints may not allow for a potting-free design.

The solid-state switch tube replacement must be robust enough to meet current performance standards. Standards that need to be considered in the design should include arcing of the Cross-Field Amplifier (CFA) including high frequency transients. Both the arc sensing and protection circuitry must be included in the design, including Transient Voltage Suppressors on all low voltage logic and control circuitry. Upon capture of arc fault data, the design must remove current from the remainder of the pulse or, in other words, truncate the pulse. The design must be capable of reliably switching high voltage up to 20,000 volts (nominal CFA operating voltage is between 12.2 to 13.6 kV), and regulating the CFA pulse currents to between 22 and 25 amperes (optimum 22.7 amperes). The pulse top current must be flat within +/- 0.1 amperes beginning 1 microsecond after the leading edge of the pulse. The rise time and fall times of the cathode current pulse must be adjustable and controllable by the new design to match the CFA operating requirements of approximately 75 to 125 nanoseconds cathode current rise and fall time. The CFA contains approximately 80 pico-farads of capacitance, for simulation purposes of capacitive charging current. The CFA cathode voltage rise time is between 80 and 130 kV/microsecond (tangent line at 70% point), and the cathode voltage fall time is between 100 and 200 nanoseconds (100% to 80% point).

The Phase I effort will not require access to classified information. If need be, data of the same level of complexity as secured data will be provided as GFI to support Phase I work. The Phase II effort will likely require secure access, and the contractor will need to be prepared for personnel and facility certification for secure access.

PHASE I: The contractor will develop concepts for a solid-state switch tube replacement that meets shipboard application requirements as presented in the description. The contractor will determine the feasibility of their innovative technology to meet Navy needs and will conduct analysis that shows their technology can transition into useful products for the Navy. Feasibility will be established by material and/or design element testing and analytical modeling or a combination of these approaches as needed to assure feasibility of their potential follow-on Phase II. The company will provide a Phase II development plan with performance goals and key technical milestones. The plan will also address technical risk reduction.

PHASE II: Based on the results of Phase I and the Phase II development plan, the contractor will develop a prototype for evaluation to determine the capability of their technology to satisfy the performance goals defined in the Phase II development plan and the Navy application requirements for the solid-state switch tube replacement. The performance will be demonstrated through prototype evaluation and modeling and/or analytical methods for all application performance parameters including electrical, mechanical, and thermal performance, maintenance and reliability. Evaluation results will be used to refine the prototype and generate an initial design that will meet Navy requirements. The contractor will prepare a Phase III development plan to transition the technology for Navy use.

PHASE III: If Phase II is successful, the contractor will support the Navy in transitioning the technology for Navy use. The contractor will develop a solid-state switch tube replacement for testing to determine its effectiveness in, and suitability for, an operationally relevant environment. The contractor will support the Navy for test and validation to certify and qualify the system for Navy use.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Commercial applications of CFAs are limited to airport and other weather use radars. These radars use CFAs because they are needed for high-power radar applications. CFAs have power output capability as high as 10 megawatts. CFAs are primarily used in the Navy to support radar systems used on the AEGIS weapons systems.

REFERENCES:
1. Rosebury, F. Handbook of Electron Tube and Vacuum Techniques. New York: American Institute of Physics, 1993.

2. Gilmour, A.S. Principles of Microwave Tubes. Massachusetts: Artech House Inc., 1986.

3. Sechi, F. & Bujatti, M. Solid-State Microwave High-Power Amplifiers. Massachusetts: Artech House, Inc., 2009.

4. Whitaker, J. Power Vacuum Tubes Handbook. Second Edition. Florida:CRC Press LLC, 1999.

KEYWORDS: Switch Tube; Solid State Modulator; Electronic Switch Driver; Power Amplifier; solid state amplifier; cross-field amplifier

** TOPIC AUTHOR (TPOC) **

DoD Notice:   Between 16 November, 2012 through 16 December 2012, you may talk directly with the Topic Authors (TPOC) to ask technical questions about the topics. Their contact information is listed above. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed starting 17 December, 2012, when DoD begins accepting proposals for this solicitation.

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