Real Time RF Range Delay Emulation Navy SBIR FY2010.1 Sol No.: Navy SBIR FY2010.1 Topic No.: N101-010 Topic Title: Real Time RF Range Delay Emulation Proposal No.: N101-010-0821 Firm: Research Associates of Syracuse 111 Dart Circle Rome, New York 13441 Contact: Paul Rivkin Phone: (315) 339-4800 Web Site: www.ras.com Abstract: This effort investigates and assesses the feasibility of a digital delay-line approach to accomplishing high-fidelity wideband RF range delay emulation. A system architecture combining wideband frequency translation with high-speed A/D and D/A conversion technologies is proposed covering the full 18GHz RF band while supporting 800MHz of instantaneous bandwidth. A digital delay-line implementation can support programmable delays up to tens of milliseconds with 250psec resolution as well as wideband linearity. Our approach to achieving wide linear dynamic range (in excess of 55dB) minimizes signal distortion from several aspects including: (1) the active time-delay mechanism (i.e. discrete-time delay and linear interpolation) has a highly linear transfer function, (2) we exploit recent performance gains in COTS analog / digital conversion technologies including high sample rate / high resolution devices with excellent spur-free dynamic range (SFDR) and Signal-to-Noise Ratio (SNR) (60dB or better), and (3) harness the power of digital signal processing and in-house receiver distortion analysis expertise to accomplish a high degree of equalization and spur rejection to compensate for the distortion of RF/IF analog components. Our digital approach will also provide enhanced features including the ability to apply independent time delays simultaneously to multiple (spectrally non-overlapping) signals within a common instantaneous band. Benefits: The RF range-delay emulator concept developed during this effort will provide the military with the capability to accurately model one-way range delay of injected wideband signals with broad RF coverage. This capability will provide a cost savings to the government by supporting the test and evaluation of DRFM systems within an installed system test facility. Other areas that may benefit from an ISTF with this capability include the evaluation of EW/ELINT systems employing TDOA geolocation or systems implementing precision PRI pulse processing techniques, for example. Specific key benefits of the proposed approach include: 1) Precise dynamic control of range-delay with potential for very long delays possible, 2) Significant instantaneous linear dynamic range through reconfigurable digital equalization and spurious rejection to compensate for hardware component non-linearities across wide instantaneous signal bandwidths and broad RF coverage, 3) Capability to account for ISTF infrastructure delay and signal level variability via front-end tuner gain control, 4) Flexible interface with host test facility, with JIMM compatibility and supporting rapid dynamic target state updates. Potential applications in the private sector could include test and evaluation of commercial cellular or RF data links operating in fading channel environments. Return