AN OPTICAL PROCESSOR FOR PASSIVE RF INTERFEROMETRY

OPTICAL COMPUTING TECHNIQUES PROMISE DRAMATIC IMPROVEMENTS IN THE EFFICIENCY OF DIRECTION FINDING AND SIGNAL CHARACTERIZATION WITH PASSIVE RF PLANAR ARRAY INTERFEROMETRY. PLANAR ARRAY INTERFEROMETRY CAN PROVIDE FINE RESOLUTION DIRECTION OF ARRIVAL (DOA) MEASUREMENTS SIMULTANEOUSLY FOR SIGNALS WITHIN A WIDE FIELD OF VIEW. HOWEVER, THE PROCESSING BURDEN IS ENORMOUS USING STANDARD PROCESSING ARCHITECTURES. FURTHERMORE, CHARACTERIZING A PARTICULAR DETECTED SIGNAL, FOR EXAMPLE MEASURING THE POWER SPECTRAL DENSITY, WHEN OTHER SIGNALS ARE PRESENT WITHIN THE FIELD OF VIEW REQUIRES COMPLEX PROCESSING WHEN USING STANDARD METHODS. THIS PAPER PROPOSES AN OPTICAL FIBER PROCESSING ARCHITECTURE WHICH DRAMATICALLY INCREASES THE EASE WITH WHICH THE DOA OF THE SIGNALS CAN BE OBTAINED FROM PASSIVE RF PLANAR INTERFEROMETRIC ARRAYS AND TRIVIALIZES THE PROBLEM OF CHARACTERIZING THE RF ENERGY COMING FROM A PARTICULAR LOCATION. INCLUDED IN THE PROPOSED ARCHITECTURE IS A SUBSYSTEM USING OPTICAL PROCESSING TO ISOLATE RF ENERGY COMING FROM A PARTICULAR DIRECTION AND TO GENERATE THE POWER SPECTRAL DENSITY OF THE ISOLATED RF ENERGY. THE OBJECTIVE OF THIS EFFORT IS TO ESTABLISH THE SPECIFIC DESIGN REQUIREMENTS AND TO DEFINE A BASIS FOR ASSESSING THE FEASIBILITY OF THE OPTICAL PROCESSING; TO FURTHER DEVELOP AND REFINE THE ARCHITECTURE AND ESTABLISH SYSTEM CHARACTERISTICS AND PARAMETER VALUES TO SATISFY THE REQUIREMENTS; AND TO DETERMINE THE RISK AND EFFORT REQUIRED TO DEVELOP THE OPTICAL PROCESSOR.