Digital Direction Finding

Argon Engineering Associates presents an innovative approach to Direction Finding (DF), replacing analog Butler Matrix beamforming with an all-digital adaptive beam former. Argon proposes to implement FFT channelization before beamforming using FieldProgrammable Gate Arrays (FPGAs). This allows both beamforming and advanced signal detection algorithms performed in general purpose processors to use the same underlying correlation matrix formed by multiplying pair-wise antenna inputs. Signal digitaldirection finding can be implemented on detected signals by Multiple Signal Classification (MUSIC) multipath immune MODE or other array DF algorithms.This digital architecture is investigated for aircraft DF implementation where the receivers are located with their antennas, passing digital data to FPGA and processors using Fiber Optic (FO) paths to eliminate bulky and variable RF cables that causephase errors and path loss. One of the SBIR goals is to investigate the feasibility of implementing advanced adaptive digital beamforming with a forward digitization architecture using FO digital signal routing.One of the key objectives of this SBIR is to reduce size, weight and power for Unmanned Aerial Vehicle (UAV), where the weight must be less than 200 pounds and power less than 200 watts. Employing our business model, Argon Engineering Associates plans toincorporate the primary innovative technology of digital adaptive beam-forming into the product line for integration into future LIGHTHOUSE based systems. It is fully expected that this technologies will have a direct impact to several Army, Navy andforeign programs - Aerial Common Sensor (ACS), PROPHET (Air and Ground), Ship's Signal Exploitation Equipment (SSEE) and the British Soothsayer programs.