HF Digital Receiver

ABSTRACT: Advances in digital technology have made viable the migration of RF receivers from analog RF circuitry to digital gate arrays, with corresponding improvements in spectral accuracy, stability, reliability, and re-configurability. To realize a cost effective HF digital receiver, the challenges are: implementing computationally efficient digital filters under the constraint of limited hardware resources in Field-Programmable Gate Arrays (FPGA), managing the effects of quantization errors on dynamic range and linearity, designing a cost-effective, low-noise, and high dynamic range analog front-end, and determining optimal bandwidth for narrow band operation while keeping ENOB to at least 24 bits. Visor will adapt its existing UHF digital receiver for HF application by developing new digital down-conversion logical blocks in the FPGA and demonstrating the result on a Virtex-6 prototype board. Visor will also finalize the specification of an HF digital receiver for over-the-horizon radar (OTHR), and complete a detailed design package (schematics, FPGA code, and system wiring diagrams) for a cost-effective digital receiver. We will then assess the risk factors in making prototypes for integration into an operational testbed for Phase II. With extensive radar design experience, including operational digital receivers, Visor will design and demonstrate an optimal digital receiver for OTHR applications. BENEFIT: 1. Evaluate and quantify the tradeoffs between performance and cost in HF digital receivers. 2. Identify opportunities for cost reduction in radar systems that use multiple antenna elements in an array. 3. Provide significant cost reductions for RF systems that operate in the HF band which will enable wider acceptance in commercial applications, such as remote sensing products.