TECHNOLOGY AREA(S): Air Platform, Electronics

ACQUISITION PROGRAM: PMA234 Airborne Electronic Attack Systems

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 3.5 of the Announcement. 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 and package a radio frequency (RF) to optical transmitter in a compact form factor, operating at 1.55 micron wavelengths, for wideband RF photonics applications.

DESCRIPTION: Current airborne military (mil-aero) communications and electronic warfare systems require ever increasing bandwidths while simultaneously requiring reductions in space, weight, and power (SWaP). The replacement of the coaxial cable used in various onboard RF/analog applications with RF/analog fiber optic links will provide increased immunity to electromagnetic interference, reduction in size and weight, and an increase in bandwidth. To accomplish this, transmitter modules are required to integrate lasers, optical modulators, bias control, and electronics in a compact form factor that can meet extended temperature range requirements (-40�C to 100�C) of the mil-aero environment.

Typically, RF-to-optical transmitters are made by integrating many discrete components into a single large module that routinely exceeds 300 cm^3. To facilitate use by many airborne platforms, the form factor of these transmitters must be reduced to less than 150 cm^3. Simultaneously, the transmitter must have performance requirements that support high performance RF link specifications such as RF bandwidths exceeding 18 GHz; RF noise figures below 25 dB (no RF pre-amplification) when connected directly to a separate single high current photodiode (0.7Amp/Watt responsivity); optical output powers greater than 20 mW from a single mode optical fiber; and spur free dynamic ranges above 110 dB-Hz^2/3. The transmitter output should be single longitudinal mode and have a relative intensity noise level of below -165 dBc/Hz over all RF frequencies from 1 to 18 GHz.

Higher levels of component integration that eliminate the use of optical splices will be needed as well as the development of more compact drive electronics for both quadrature modulator biasing and laser power conditioning circuits. It is also desirable for this transmitter module to have a package dimension no greater than 17.5 x 65 x 115 mm with all optical, electrical and RF connections entering and exiting though only one of the 17.5mm or 65 mm surfaces.

PHASE I: Design and develop an approach for the compact optical transmitter. Demonstrate feasibility of laser and modulator performance required as well as integration and electronic circuits strategies showing the path to meeting Phase II goals. Design and analyze a transmitter package prototype. The Phase I effort will include prototype plans to be developed under Phase II.

PHASE II: Optimize and fabricate a packaged transmitter prototype based on the Phase I design. Build the transmitter and test to meet design specifications in an RF photonic link with the minimum performance levels reached. Characterize the packaged transmitter over temperature and air platform thermal shock, temperature cycling, vibration, and mechanical shock spectrum. If necessary, perform root cause analysis and remediate package failures.

PHASE III DUAL USE APPLICATIONS: Qualify the packaged transmitter prototype and transition to manufacturing. Commercial applications include wireless networks based on remoted antennas; and analog optical sensors. Specifically, the Telecom Industry would benefit from successful technology development.

REFERENCES:

1. Urick, V.J., Willams, K.J., and McKinney, J.D. �Fundamentals of Microwave Photonics.� Wiley Series in Microwave and Optical Engineering, 2015. ISBN: 978-1-118-29320-1. DOI: 10.1002/9781119029816

2. MIL-STD-810G, Environmental Engineering Considerations and Laboratory Tests. http://everyspec.com/MIL-STD/MIL-STD-0800-0899/MIL-STD-810G_12306/

3. MIL-STD-883K, DoD Test Method Standard Microcircuits. http://www.dscc.dla.mil/downloads/milspec/docs/mil-std-883/std883.pdf

4. MIL-STD-1678, Fiber Optic Cabling Systems Requirements and Measurements. http://www.landandmaritime.dla.mil/programs/milspec/ListDocs.aspx?BasicDoc=MIL-STD-1678

5. MIL-STD-38534J, General Specification for Hybrid Microcircuits. http://www.landandmaritime.dla.mil/programs/milspec/ListDocs.aspx?BasicDoc=MIL-PRF-38534

6. DO-160F Environmental Conditions and Test Procedures for Airborne Equipment. http://www.rtca.org/store_product.asp?prodid=759-

KEYWORDS: Radio Frequency-Over-Fiber; Transmitter; Laser; Modulator; Integrated; Packaging