DIRECT TO PHASE II - Modernized Sonar Transmit Electronics

Navy SBIR 24.2 - Topic N242-D11
NAVSEA - Naval Sea Systems Command
Pre-release 4/17/24   Opened to accept proposals 5/15/24   Closes 6/12/24 12:00pm ET    [ View Q&A ]

N242-D11 TITLE: DIRECT TO PHASE II: Modernized Sonar Transmit Electronics

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Integrated Sensing and Cyber; Microelectronics

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 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 an architecture for modernized digital transmit electronics to power future hull-mounted acoustic arrays within the AN/SQQ-89A(V)15 sonar system.

DESCRIPTION: Sonar systems that include active sonar transmissions rely on transmit electronics to provide power to the transducers that produce sound in the ocean. Put simply, a transducer performs the transformation between an electrical signal in volts (V) and a physical quantity such as displacement of the head at the end of a stack of piezo-electric ceramics. Transmitters transform volts into amps (A) and vice versa.

The AN/SQS-53 hull mounted sonar array is a large bulb-like structure built into the bows of ships below the water line. Ships fitted with AN/SQS-53 include U.S. Navy Arleigh Burke-class destroyers, Ticonderoga-class cruisers, and select Japanese Maritime Self-Defense Force destroyers. The AN/SQS-53 hull-mounted sonar has a nominal source level of 235 decibels (dB) re 1 µPa and transmits at a center frequency of approximately 3 kHz. The AN/SQS-53 includes 576 TR-343 transducer tube assemblies arranged in staves of 8 transducers every 5 degrees azimuthally. Each TR-343 transducer assembly is capable of a) active acoustic transmit or creating noise (or sound pressure level) in response to voltage from the transmit electronics and b) passive acoustic detection or detecting incoming pressure changes and transforming that pressure into voltage to be sent to the transmit electronics.

The current transmit electronics for the AN/SQS-53C which perform the transformation between voltage and amps for both active acoustic transmit and passive acoustic detection consists of three racks of analog electronic components to support the 576 transducers in the AN/SQS-53C. These analog electronic components have reached end of life and must be modernized to support ongoing maintenance and future acquisition of new systems.

The Navy desires prototype transmit electronics that can transform the digital waveforms into voltage signals at individual TR-343 transducers to accommodate the requisite displacement of the ceramic assembly associated with active and passive acoustic functionality at the nominal source level and center frequency. There is nothing available commercially that can accomplish the required transformation. The prototype transmit electronics must be scalable to support the entire set of 576 transducers while fitting within the space, weight, and power (SWaP) envelope associated with the existing analog power transmit capability. The SWaP and notional full rate production cost targets are:

• Space: 3 transmit cabinets, each with height of 76", width of 21" and depth of 22"

• Weight: 2000 lbs. for all three cabinets, not to include cable runs extending beyond the transmit cabinets

• Power: TBD

• Full Rate Product Cost (FY24 dollars): Not To Exceed $2.5M per transmit electronics assembly

Innovation is anticipated to handle the current AN/SQS-53C source levels using digital transmit electronics as well as make the design extensible to future hull arrays with transducers that may utilize either textured ceramics or single crystal ceramics. Innovation is also anticipated to meet the Grade A shock requirements, which equates to the system remaining functional for any shock conditions where crew would remain alive to continue use of the AN/SQS-53C hull array.

PHASE I: For a Direct to Phase II topic, the Government expects that the small business would have accomplished the following in a Phase I-type effort and developed a concept for a workable prototype or design to address, at a minimum, the basic requirements of the stated objective above. The below actions would be required in order to satisfy the requirements of Phase I:

• A concept for modern digital transmit electronics that is clearly extensible to a TR-343 transducer.

• A notional architecture to support the conclusion that the proposed digital transmit electronics could fit within the SWaP of the current analog transmit electronics associated with the AN/SQS-53C.

• Documentation describing completion of an experimental proof of concept (a manufacturing readiness level (MRL) of 3).

• Explanation of how the company could ramp up production to support acquisition of full transmit electronic units within a year of completion of the Phase II effort (4 years after award of the Phase II base).

FEASIBILITY DOCUMENTATION: Offerors interested in participating in Direct to Phase II must include in their response to this topic Phase I feasibility documentation that substantiates the scientific and technical merit and Phase I feasibility described in Phase I above has been met (i.e., the small business must have performed Phase I-type research and development related to the topic NOT solely based on work performed under prior or ongoing federally funded SBIR/STTR work) and describe the potential commercialization applications. The documentation provided must validate that the proposer has completed development of technology as stated in Phase I above. Documentation should include all relevant information including, but not limited to: technical reports, test data, prototype designs/models, and performance goals/results. Work submitted within the feasibility documentation must have been substantially performed by the offeror and/or the principal investigator (PI). Read and follow all of the DON SBIR 24.2 Direct to Phase II Broad Agency Announcement (BAA) Instructions. Phase I proposals will NOT be accepted for this topic.

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by 32 U.S.C. § 2004.20 et seq., National Industrial Security Program Executive Agent and Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence and Security Agency (DCSA) formerly Defense Security Service (DSS). The selected contractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances. This will allow contractor personnel to perform on advanced phases of this project as set forth by DCSA and NAVSEA in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material during the advanced phases of this contract IAW the National Industrial Security Program Operating Manual (NISPOM), which can be found at Title 32, Part 2004.20 of the Code of Federal Regulations. Reference: National Industrial Security Program Executive Agent and Operating Manual (NISP), 32 U.S.C. § 2004.20 et seq. (1993).

PHASE II: Develop and deliver prototype transmit electronics that can support a representative segment of an AN/SQS-53C hull array, nominally 7 staves of 6-8 transducers. The government will review the design before the awardee acquires design-specific components. The government will also work with the awardee to conduct tests of appropriate collections of prototype transmit electronics (e.g., examples to demonstrate reliable performance with a single transducer, assemblies that can manage a representative stave of 6-8 transducers, and finally that the full prototype that can handle at least 5-7 staves of transducers (20-30 degrees of azimuthal coverage)).

The final Phase II report shall contain a design for how the prototype can be scaled to accommodate a full AN/SQS-53C transducer set and the associated SWaP plus the full rate production cost estimated for the full transducer set.

Work under Phase II is anticipated to include at least discussion of classified information. A DD254 will be issued approximately 2 months after Phase II award to enable classified discussion between the government and the awardee.

PHASE III DUAL USE APPLICATIONS: Assist the Navy in transitioning the transmit electronics by a) a full engineering demonstration model (EDM) of the modernized transmit electronics for a full AN/SQS-53C array and b) low rate initial production of the company’s modernized transmit electronics. Provide services associated with test and evaluation of the EDM and LRIP transmit electronics to include environmental qualification testing (EQT) appropriate for Grade A Shock.

The Navy anticipates that the technology developed under this Phase II effort can also be used to provide acoustic transmit electronics for active sonar systems used for exploration by commercial sectors such as the oil and gas industry.


  1. Miller, Sarah K. "NSWC Crane Exceeds Significant 50k Transducer-Delivery Milestone, Boosting Undersea Sonar Capabilities for Navy Fleet." NAVSEA News, 9 Dec 2021.
  2. "AN/SQQ-89(V) Undersea Warfare Anti-Submarine Warfare Combat System." Navy Fact File, 20 Sep 2021.
  3. "AN/SQS-53 Sonar." Military Analysis Network, 30 Jun 1999.
  4. "AN/SQS-53C Transmitter Infrastructure, solicitation N00024-18-R-5205." 26 Jul 2018.

KEYWORDS: Transmit Electronics; Active Acoustic Transmit; Passive Acoustic Detection; Hull-Mounted Sonar Array; transform volts into amps; Grade A Shock


The Navy Topic above is an "unofficial" copy from the Navy Topics in the DoD 24.2 SBIR BAA. Please see the official DoD Topic website at for any updates.

The DoD issued its Navy 24.2 SBIR Topics pre-release on April 17, 2024 which opens to receive proposals on May 15, 2024, and closes June 12, 2024 (12:00pm ET).

Direct Contact with Topic Authors: During the pre-release period (April 17, through May 14, 2024) proposing firms have an opportunity to directly contact the Technical Point of Contact (TPOC) to ask technical questions about the specific BAA topic. Once DoD begins accepting proposals on May 15, 2024 no further direct contact between proposers and topic authors is allowed unless the Topic Author is responding to a question submitted during the Pre-release period.

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Topic Q & A

05/17/24  Q. 1) Will the Navy make Government Furnished Equipment (GFE) available for characterization, evaluation, and testing purposes?
2) Can Government Furnished Information (GFI) associated with the SQS-53C Front End be made available?
3) Is the Navy looking to change the hull array and processing units?
4) What are the maximum data rate and bandwidth requirements for the digital signal processing component of the transmit electronics to ensure no loss in signal fidelity during active sonar operations?
5) Can you provide the specifications for the power supply, including voltage and current stability requirements, for the digital transmit electronics to ensure consistent performance across all operating conditions?
6) What specific shock test standards and parameters does the new transmit electronics need to meet?
7) What are the maximum allowable temperatures for the electronic components within the transmit cabinets?
8) The announcement says there are three transmit cabinets. We believe the system under consideration has 6. Please clarify.
9) A goal of the SBIR is achieving a solution that also control costs. Can a reference be provided that allows us to understand what would constitute a cost saving?
10) Can the 53C Front End functionality be summarized?
11) Who currently builds the existing design?
   A. 1) The Navy can make GFE available as part of the SBIR Phase II. The Navy can also make facilities available for testing purposes.
2) After contract award, the Navy can provide Level III Technical Data Packages associated with the SQS-53C Front End. Other higher level GFI such as schematics, pictures, manuals, and specifications can also be made available.
3) No. This SBIR is strictly focused on the Transmitter Cabinets and Transmit/Receive Switch cabinet that make up the SQS-53C Front End. Ideally the proposed changes surgically and strategically upgrade or change the cabinets payload. Ideally, the technology developed by this SBIR could be backwards compatible.
4) a. The digital signal processing which is part of the processing units is not part of the SBIR. However the AN/SQS-53C is a mid-frequency sonar, which refers to sonars that function between 1 KHz and 10 KHz. Each transducer acts to both transmit and receive. It is more important that the receive function of the system be high fidelity and accurate.
   b. Exact values for minimum sample rate, dynamic range, signal to noise ratio (for transmit) and dBV self-noise (for receive) will be provided upon contract award.
5) a. MIL-STD-1399 Section 300 describes electrical interface characteristics for shipboard equipment utilizing AC electric power to ensure compatibility between the user equipment and the electric power system.
   b. The High Voltage Power Supplies (HPVSs) receive 440 VAC 60 Hz 3-phase shipboard power.
   c. Additional information can be provided upon contract award.
6) MIL-DTL-901E for Grade A equipment
7) a. The Xmit cabinet should be capable of operating in a 45°C environment for up to 24 hours.
   b. For personnel safety, any exposed surfaces that exceed 60° should be labeled with a temperature hazard warning.
   c. The current Xmit cabinet design is water-cooled.
8) Correct, the SQS-53C does have six (6) XMIT cabinets.
9)a. Minimizing or removing the following manufacturing problems will address the main cost drivers:
i. Usage of non-standard electronic components
ii. Labor intensive processes
iii. Dependence on components with 18+ lead times
10) a. In essence, the SQS-53C Front End serves to
i. Power Amplify analog signals going to the transducers,
ii. Pre-amplify analog signals coming from the transducers
iii. Control the path for the signals whether the system is receiving or transmitting, and
iv. Monitor its own health by allowing Performance Monitoring / fault Localization (PMFL) functions
b. In terms of type of modules, in general, there are:
i. Hi Voltage Power Supplies
ii. Low Voltage Power Supplies
iii. Voltage Regulators
iv. Relay “buckets”
v. Power Amplifiers
vi. Preamplifiers
11) Lockheed Martin Corporation RMS and Advanced Acoustic Concepts, LLC

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