The Defense Advanced Research Projects Agency (DARPA) is soliciting innovative research proposals in the area of linear photonic radio frequency (RF) front-ends supporting the need for extremely high dynamic range microwave receivers. Proposed research should investigate innovative microwave photonic transmission approaches that enable revolutionary advances in science, devices or systems. Specifically excluded is research that primarily results in evolutionary improvement to the existing state of practice.
The objective of PHOR-FRONT is to develop and demonstrate intrinsically linear, high sensitivity optical transmission techniques which can serve as the analog front-end of a digital microwave receiver. A key objective is to replace conventional electronic low-noise amplifiers, mixers and copper cables with highly linear microwave photonic links providing RF gain, low Noise Figure (NF), frequency down-conversion to Intermediate Frequency (IF) or baseband, and most importantly, extremely high two-tone Spurious-Free Dynamic Range (SFDR). With the understanding that processing wideband RF antenna signals into High Dynamic Range (HDR) digital bit streams is an important military thrust, this development serves to provide the critical optoelectronic (OE) infrastructure allowing a universal RF front-end that enables remote HDR digital processing. This solicitation specifically addresses the development of the OE modules deemed most critical to achieving the targeted bandwidth, SFDR and NF requirements for transmission and down-conversion of microwave antenna signals. The use of 1550 nm wavelength coherent optical transmission techniques incorporating LINEAR Phase Modulation (PM) and LINEAR phase demodulation is highly desirable and considered an attractive approach in achieving the required NF and SFDR. As such, the 1550 nm coherent optical oscillator and the linear phase demodulator, e.g. a balanced optical mixer phase-locked-loop discriminator, are considered the most critical modules necessary to achieve this goal. Optical phase modulation at the transmitter side, although necessary, is considered a lower risk element of the photonic front-end and not considered part of this solicitation. The back-end analog-to-digital converter (ADC) is also not addressed in this solicitation; however, the proposed photonic RF front-end approaches should be fully compatible with HDR ADC back-end implementations. In fact, the OE module flow-down requirements have been aligned with projected (less than 10 year) ADC performance levels for bandwidth and resolution.
The targeted end-of-program performance goal is to provide at least 90 dB of 2-tone SFDR in a 500 MHz Instantaneous Bandwidth (IBW), at any center frequency within the desired operating frequency range of 0.5-18 GHz. This multi-octave range of RF signals will result from multiple antenna outputs, and it can be assumed that the frequency band of each antenna covers less than an octave. A photonic RF front-end NF of 3 dB is targeted in association with the SFDR goal. It is envisioned that PHOR-FRONT will enable a dramatic leap in performance for applications such as channelized Electronic Warfare (EW) receivers. In this example application, each antenna feed would be applied to individual PHOR-FRONT links, which in turn provide input signals for individual receiver systems.
For the development of the PHOR-FRONT modules, DARPA seeks innovative proposals in the following device areas:
I. 1550 nm Coherent Optical Oscillator
The first major interest of the PHOR-FRONT program is the development and demonstration of a narrow-linewidth, low-noise, high power, frequency-stabilized coherent optical oscillator. The spectral region of interest for this single frequency laser is the 1550 nm communications band, where a wealth of supporting optoelectronic component infrastructure exists. In addition to supporting highly linear analog photonic links, the challenging performance specification goals targeted for the laser have been chosen to meet other coherent oscillator application needs. Innovative semiconductor, solid-state and fiber laser approaches to producing compact laser modules that can meet these challenging performance specifications are solicited. This area of interest has four sub-tasks:
A. Develop and demonstrate a narrow-linewidth (less than 10 Hz) single-mode laser design at 1550 nm wavelength that can readily scale in output power (greater than 1 W) and show a path to high wall plug efficiency (greater than 20 percent);
B. Incorporate Amplitude Modulation (AM) & Frequency Modulation (FM) laser noise reduction techniques into the laser design enabling shot-noise-limited performance to be obtained at small frequency offsets from the optical carrier (less than 1 MHz);
C. Develop and demonstrate a precise high-resolution frequency stabilization method for realizing long-term absolute wavelength stability (less than 100 kHz total excursion); and
D. Demonstrate and deliver the laser performance required to realize the photonic RF front-end receiver NF and SFDR to be demonstrated in conjunction with the second area of interest below.
The goal at the end of Phase I of the program (see Program Scope below) is to fabricate and demonstrate a functional coherent optical oscillator, and to demonstrate a design path to increased performance levels. The Program goal, at the end of Phase II, is to fabricate and demonstrate the optical oscillator with full performance specifications enabling the targeted photonic link SNR, NF and SFDR goals to be achieved in conjunction with the second area of interest below.
II. Linear Optical Phase Demodulator
The second major area of interest is the design, fabrication and demonstration of a strictly linear optical phase demodulator to be used in conjunction with a linear optical PM transmitter. Phase demodulation techniques that produce intrinsically linear receiver transfer characteristics, as opposed to relying principally on intermodulation distortion (IMD) cancellation methods, are central to this task. One possible example of a coherent receiver that falls within the scope of this task area is a balanced mixer optical phase-locked-loop (OPLL) discriminator. In this case, the OPLL output error signal can be configured to instantaneously track the phase of the input signal, i.e. a linear PM demodulator. Coherent receivers for 0.5-18 GHz phase modulated optical signals with 500 MHz IBW providing greater than90 dB SFDR are of interest. Coherent phase-tracking/phase-nulling approaches as well as other novel approaches for achieving strictly linear coherent phase demodulation and downconversion will be considered, provided that detailed analyses and simulations support the RF link performance claims.
It is important to note a few considerations pertaining to the envisioned military applications. The targeted RF antenna applications for space-based, air-borne, maritime or ground-based military platforms dictate that the signal laser (1550 nm coherent optical oscillator) can be remotely co-located with the receiver optoelectronics, providing several local oscillator and feedback implementation options that can be explored. In addition, the use of polarization-maintaining fiber can be assumed for the short antenna/processor fiber runs, eliminating the need for polarization diversity receiver techniques to be considered. These considerations should simplify the coherent receiver implementation required for this task area.
This area of interest has four general sub-tasks:
A. Develop and demonstrate a phase demodulator design at a wavelength of 1550 nm that provides highly linear (OIP3 greater than +75 dBm) performance in conjunction with a large 1 dB compression-point dynamic range (greater than 175 dB);
B. Develop receiver and link models to simulate and predict both receiver and link performance levels for given laser and modulator parameters;
C. Identify/analyze major sources of noise and nonlinearities in the coherent link that are related to the receiver and incorporate mitigation techniques; and
D. Demonstrate and deliver the coherent optical receiver performance required to realize the photonic RF front-end receiver NF and SFDR to be demonstrated in conjunction with the first area of interest above.
For all proposed approaches and implementations, fully functional linear phase demodulation chips/modules are to be developed and demonstrated. The proposal should provide simulation and analysis depicting the expected link linearity of the proposed approach using 1550 nm laser specifications similar to that being developed in Area I of this solicitation. Proposals should clearly describe all major parametric dependencies of the link linearity in the system, including system components not addressed in this solicitation (e.g. front-end optical modulator). The goal at the end of Phase I of the program (see Program Scope below) is to fabricate and demonstrate a functional linear optical phase discriminator, and to demonstrate a design and integration path to increased performance levels. The Program goal, at the end of Phase II, is to fabricate and demonstrate the optical phase discriminator with full performance specifications enabling the targeted photonic link bandwidth, NF and SFDR goals to be achieved.
PHOR-FRONT offerors are encouraged to submit innovative proposals that address either or both of the areas of interest, as proposers are not required to address both topics. Although not a requirement, teaming is encouraged where warranted, especially under Area II which would necessitate integration of various photonic and electronic technologies.
The selected performers will be required to deliver individual devices and groups of devices (subsystems) that form analog photonic RF front-end building blocks at appropriate intervals within the program to a DARPA-designated facility. Offerors are also asked to submit a list and timetable of deliverables.
Additional information on these technology areas is provided in the Areas of Interest section of the BAA 05-20 Proposer Information Pamphlet referenced below.
The PHOR-FRONT program will consist of a 15 month Phase I effort with contractor defined Go Ahead critical milestones at the end of 12 months. This will be followed by a 15-month Phase II option to achieve the full performance targets if not achievable in Phase I. Clearly stated, quantitative milestones at 12, 21 and 30 months into the program are required. Offerors are strongly encouraged (Evaluation Criteria (3)) to pursue aggressive development schedules towards meeting the program goals in a most timely manner. Organizations wishing to participate in Phase II should include it as an option in their proposal. Multiple awards are anticipated. Collaborative efforts/teaming including different expertise such as, but not limited to, design, fabrication, integration and packaging are encouraged, but not required. Cost sharing is not required and is not an evaluation criterion, but is encouraged where there is a reasonable probability of a potential commercial application related to the proposed research and development effort. Questions concerning this BAA may be directed to the technical POC for this effort, Dr. Steve Pappert, phone: (571) 218-4679, fax: (703) 696-2206, electronic mail: firstname.lastname@example.org .
Proposers must obtain a pamphlet entitled ?BAA 05-20, Linear Photonic RF Front-End Technology (PHOR-FRONT), Proposer Information Pamphlet? which provides further information on the objectives of the PHOR-FRONT BAA, the submission, evaluation, and funding processes, proposal formats, and other general information. This pamphlet may be obtained from the FedBizOpps website: http://www.fedbizopps.gov/, the World Wide Web (WWW) at URL http://www.darpa.mil/ or by fax, electronic mail, or mail request to the administrative contact address given below. Proposals not meeting the format described in the pamphlet may not be reviewed. An original and nine (9) copies of the full proposal as specified in the Proposer Information Pamphlet, along with two (2) electronic copies (i.e., two separate disks) must be submitted to DARPA/MTO, 3701 North Fairfax Drive, Arlington, VA 22203-1714 (Attn.: BAA 05-20) on or before 4:00 p.m., local time, Friday, April 29, 2005, in order to be considered during the initial round of selections; however, proposals received after this deadline may be received and evaluated up to one year from date of posting on FedBizOpps. File formats for the electronic copies shall be PDF and MS-Word-readable. Media for each copy may be a single CD-ROM, a single 100 Megabyte Iomega Zip (registered) disk, or a single 3.5-inch High Density MS-DOS formatted 1.44 Megabyte diskette. Each disk must be clearly labeled with BAA 05-20, proposer organization, proposal title (short title recommended), and Copy number __ of 2. Full proposals submitted after the due date specified in the BAA may be selected contingent upon the availability of funds. This notice, in conjunction with the BAA 05-20 Proposer Information Pamphlet, constitutes the total BAA. No additional information is available, nor will a formal RFP or other solicitation regarding this announcement be issued. Requests for the same will be disregarded. The Government reserves the right to select for award all, some, or none of the proposals received, and to make award without discussions. All responsible sources capable of satisfying the Government's needs may submit a proposal which shall be considered by DARPA. Input on technical aspects of the proposals may be solicited by DARPA from non-Government consultants /experts who are bound by appropriate non-disclosure requirements. Non-Government technical consultants/experts will not have access to proposals that are labeled by their offerors as ?Government Only?. Historically Black Colleges and Universities (HBCUs), Minority Institutions (MIs), and Small and Small Disadvantaged Business Concerns are encouraged to submit proposals and join others in submitting proposals; however, no portion of this BAA will be set aside for these organizations' participation due to the impracticality of reserving discrete or severable areas of research in Linear Photonic RF Front-End Technology (PHOR-FRONT).
All administrative correspondence and questions on this solicitation, including requests for information on how to submit a proposal abstract or full proposal to this BAA, should be directed to one of the administrative addresses below; e-mail or fax is preferred. DARPA intends to use electronic mail and fax for correspondence regarding BAA 05-20. Proposals and proposal abstracts may not be submitted by fax or e-mail; any so sent will be disregarded. DARPA encourages use of the WWW for retrieving the Proposer Information Pamphlet and any other related information that may subsequently be provided.
Evaluation of full proposals will be accomplished through a technical review of each proposal using the following criteria, which are listed in descending order of relative importance: (l) overall scientific and technical merit, (2) potential contribution and relevance to DARPA mission, (3) offeror's ability and aggressiveness to propose and execute a challenging development schedule with ambitious performance metrics, (4) plans and capability to accomplish technology transition, (5) offeror's capabilities and related experience, and (6) cost realism. Note: cost realism will only be significant in proposals which have significantly under or over-estimated the cost to complete their effort.
The administrative addresses for this BAA are:
Fax: (703) 696-2206 (Addressed to: DARPA/MTO, BAA 05-20),
Electronic Mail: BAA05email@example.com
Mail: DARPA/MTO, ATTN: BAA 05-20
3701 North Fairfax Drive
Arlington, VA 22203-1714
This announcement and the Proposer Information Pamphlet may be retrieved via the WWW at URL http://www.darpa.mil/ in the solicitations area.
Who can apply:
Eligible functional categories:
Research and Technology Development
Linear Photonic RF Front-End Technology (PHOR-FRONT)
If you have problems accessing the full announcement, please contact:
Department of Defense, Defense Advanced Research Projects Agency, Contracts Management Office