|Acquisition Program: ||PMW-180 / Ships Signal Exploitation Equipment Increment F / ACAT II|
| ||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: ||To apply state-of-the-art cutting-edge digital technologies to improve shipboard wide-band receiver systems performances in high EMI (electromagnetic interference) environments.
|| Description: ||The current electromagnetic environment of Naval platforms is cluttered with transmitters that cover large portions of the EM (electromagnetic) spectrum. The large number of transmitters coupled with the high power levels cause harsh EMI that severely limits wide-band receiver systems operations without proper mitigation. The current state of the EMIenvironment pushes the limits of conventional technologies. These technologies, although adequate in the past, are quickly becoming limiting factors. As a result, critical shipboard functions such as signal acquisition and real-time direction finding (DF) are degraded well below specified requirements.
Advances in state-of-the-art digital technologies promise to provide fully operational shipboard ultrawideband receiver systems, not limited by EMI. These advances such as direct digital conversion have extended the ranges of key performance parameters (power tolerance, dynamic range, sensitivity, sample rates, etc) beyond conventional limits.
Current conventional wideband receiver systems employ multiple analog-to-digital converter (ADC) cards. Current state-of-the-art ADC cards require down conversion, which limits dynamic range and in current configuration require coherent coupling, which increases system complexity.
The goal of this work is to build a single unit multi-channel phase-coherent all-digital receiver system. This receiver will provide direct digitization of the RF spectrum to increase system dynamic range and to increase access to more of the RF spectrum. Reduction from the current multiple ADC system to a single unit all-digital receiver will not only save space but also improve performance and cost. As an integral part of the Naval platform wideband receiver system, the all-digital receiver will be NESI compliant and will interface to the required data formats.
|| ||PHASE I: Provide specifications and initial design for a single unit multi-channel phase-coherent directional all-digital receiver. The receiver will meet and exceed existing and future requirements of Naval platform wide-band receiver systems.
|| ||PHASE II: Build and deliver a prototype system outlined in Phase I. Perform laboratory and field testing. Field testing will be performed in an environment simulating conditions aboard Naval platforms including use of state-of-the art antennas.
|| ||PHASE III: Provide modifications to an existing wide-band receiver system for incorporation of the new multi-channel phase-coherent all-digital receiver. Provide continued testing in an actual platform environment using current and state-of-the-art antennas (such as the Tapered Slot Antenna (TSA) array). Provide plan for transition of technology into Naval operations.
PRIVATE SECTOR COMMERCIAL POTENTIAL/|| ||DUAL-USE APPLICATIONS: As wireless technology becomes more prevalent in society, directional accuracy will become more and more valued. Many devices in small areas will begin to demand distinction with the techniques expected to evolve here.
|| References: ||1. O.A. Mukhanov et al, "Superconducting Analog-to Digital Converters", Proc. IEEE, 92(10) pp. 1564-5.
2. J. Rosa, "Direct Digitization Using Superconducting Data Converters”, RF Design, March 2005, pp. 40-46.|
|Keywords: ||high dynamic range; digital down conversion; DF accuracy; phase-coherent; wideband|