N151-039 TITLE: Compact, Low-Voltage, Multiple-Beam Electron Gun for High-Power Miniature Millimeter-Wave Amplifiers

TECHNOLOGY AREAS: Sensors, Electronics, Battlespace

ACQUISITION PROGRAM: PEO IWS 2, Above Water 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. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop a multiple-beam electron gun with permanent magnet focusing for a broadband, millimeter-wave amplifier with reduced size, weight, and power requirements.

DESCRIPTION: The Navy requires high-power, low-volume, reduced-weight, efficient and affordable millimeter-wave amplifiers for Electronic Warfare (EW) systems. The requirement for high power in a small, lightweight package is acute in some cases. Vacuum electronic devices have demonstrated the ability to deliver single-device powers in excess of projected solid-state amplifier powers, particularly at millimeter-wave frequencies. Millimeter-Wave (MMW) amplifiers are the key component in future transmitters used for electronic attack, high-data-rate communications, and radar. New and next-generation MMW transmitters must operate at higher frequencies and generate significantly higher RF power per unit mass than has been achieved today. The Navy needs innovative devices to provide mission-critical capabilities such as improved self-protection against emerging anti-ship missile threats, increased operating range, high communications data rates, and all-weather operation for diverse platforms (including small autonomous platforms). The Navy seeks an enabling technology for a new class of affordable, miniature, high-power MMW amplifiers suitable for multi-platform applications. This technology will ultimately increase MMW amplifier specific power density (defined as RF output power per unit size or weight) by more than a factor of five over the current state-of-the-art.

Vacuum electronic (VE) slow-wave amplifiers have a demonstrated ability to deliver single-device power well in excess of existing or projected solid-state amplifier power in the MMW range, with higher efficiency because of residual energy recovery by depressed electron beam collectors. High output power and low total power consumption make VE amplifiers very attractive for new systems. However, the most recent advances in the power and bandwidth of VE amplifiers have been for devices operating at moderate-to-high voltages (typically, above 15 kilovolts (kV)). These high operating voltages necessitate longer traveling-wave circuits and significantly increase the size and weight of the amplifier (particularly the permanent magnet focusing system) and the power supply. Lower operating voltages have obvious benefits in the size, weight, reliability, and cost of VE amplifiers. However, achieving high power at low voltage is quite difficult and generally requires a distributed electron beam (for example, multiple parallel beams) to achieve high current at low voltage. As an example of the impressive performance made possible by a low-voltage, multiple-beam approach, engineers at Istok Corporation, Russia, have reported 1-kiloWatt (kW) narrow-band amplifiers at frequencies of 15 -17 Gigahertz (GHz) (Ref.1). These amplifiers operate at voltages of a few kilovolts and have a specific power density of about 1 kiloWatt/kilogram (kW/kg) (including the magnet). Expansion of this low-voltage, multiple-beam technology to wide-band MMW slow-wave amplifiers has great potential for the development of lightweight, high-specific-power-density miniature traveling-wave tube (TWT) amplifiers suitable for applications on a wide variety of platforms. However, significant improvements in beam brightness are needed to transport the multiple beams through the smaller diameter beam tunnels required for higher frequency traveling-wave circuits.

To enable the development of high-power, compact, low-voltage MMW amplifiers, the Navy is seeking innovative electron gun and permanent magnet beam transport approaches based on multiple-beam technology. Compact, multiple-beam devices represent an emerging technology made possible by recent advances in three-dimensional computational modeling (Refs. 2, 3) and the development of advanced high-current-density thermionic cathodes (Ref. 4). The focus of this effort is development of the multiple-beam gun and corresponding permanent magnet design for integration with a compatible Ka-band circuit. The specific power density is a key metric. A successful design will exceed 500 Watts/kilogram (W/kg), which includes the weight of the magnets. The new technology will be consistent with a compact transmitter footprint with minimized system cost, and minimal beam interception from the electron gun to the collector. An expected by-product of the research and development of the hardware is the establishment of a design methodology, scalable in power and frequency, which makes use of and expands upon the potential of modern 3-Dimensional (3D) design codes.

PHASE I: The company will develop a concept for a multiple-beam electron gun and permanent magnet transport system that meets the requirements as stated in the description section. The company will demonstrate the feasibility of the concept in meeting Navy needs and will establish that the concept can be feasibly developed into a useful product for the Navy. Analytical methods or computational modeling will establish feasibility.

PHASE II: Based on the results of Phase I and the Phase II contract statement of work, the company will develop a prototype multiple-beam electron gun and permanent magnet transport system for evaluation. The prototype will be evaluated to determine its capability in meeting Navy requirements for the multiple-beam electron gun and permanent magnet transport system. Evaluation results will be used to refine the prototype into a design that will meet Navy requirements. The company will prepare a Phase III development plan to transition the technology for Navy use.

PHASE III: The company will be expected to support the Navy in transitioning the technology for Navy use. The company will develop the multiple-beam electron gun and permanent magnet transport system according to the Phase III development plan for evaluation to determine its effectiveness in an operationally relevant environment. The company 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 multiple-beam amplifier technology include broadband high-power amplifiers for commercial satellite up-links and point-to-multipoint wireless broadband "last mile" applications, where the low operating voltage is attractive due to reduced costs and increased reliability.

REFERENCES:
1. Korolev, Alexander, Zaitsev, Sergei, Golenitskij, Ivan, Zhary, Yevgeny, Zakurdayev, Anatoli, Lopin, Michael, Meleshkevich, Pavel, Gelvich, Edward, Negirev, Alexander, Pobedonostsev, Alexander, Poogin, Victor, Homich, Vladimir, and Kargin, Alexander. "Traditional and Novel Vacuum Electron Devices." IEEE Trans. Electron Devices 48 December 2001: pp. 2929- 2937.

2. Nguyen, Khanh, Pershing, Dean, Abe, David, Miram, George, and Levush, Baruch. "Eighteen-Beam Gun Design for High Power, High Repetition Rate, Broadband Multiple-Beam Klystrons." IEEE Trans. Plasma Science 33 April 2005: pp. 685-695.

3. Ives, Lawrence, Attarian, Adam, Bui, Thuc, Read, Michael, David, John, Tran, Hien, Tallis, William, Davis, Steven, Gadson, Sean, Blanch, Noah, Brown, David, and Kiley, Erin. "Computational Design of Asymmetric Electron Beam Devices." IEEE Trans. Electron Devices 56 May 2009: pp. 753-761.

4. Wang, Yiman, Wang, Jinshu, Liu, Wei, Zhang, Xizhu, and Li, Lili. "Emission Mechanism of High Current Density Scandia-Doped Dispenser Cathodes." Journal of Vacuum Science & Technology B 29 July/August 2011: pp: 04E106-1 - 04E106-9.

KEYWORDS: Electron beam; millimeter-wave; permanent magnet; multiple-beam; vacuum electronic; slow-wave amplifier

** TOPIC AUTHOR (TPOC) **

DoD Notice:   Between December 12, 2014 and January 14, 2015 you may talk directly with the Topic Authors (TPOC) to ask technical questions about the topics. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed starting January 15, 2015 , when DoD begins accepting proposals for this solicitation.

However, proposers may still submit written questions about solicitation topics through the DoD's SBIR/STTR Interactive Topic Information System (SITIS), in which the questioner and respondent remain anonymous and all questions and answers are posted electronically for general viewing until the solicitation closes. All proposers are advised to monitor SITIS (15.1 Q&A) during the solicitation period for questions and answers, and other significant information, relevant to the SBIR 15.1 topic under which they are proposing.

If you have general questions about DoD SBIR program, please contact the DoD SBIR Help Desk at (866) 724-7457 or webmail link.