PHASED ARRAY ANTENNA

THE WEIGHT AND COST OF FIXED PHASED ARRAYS PRECLUDES THEIR DEPLOYMENT ON MANY SHIPS THAT CURRENTLY HAVE INADEQUATE RADAR CAPABILITY. AN ALTERNATIVE APPROACH THAT COULD SATISFY THIS NEED WOULD BE A BACK-TO-BACK, ROTATING PHASED ARRAY RADAR. WITH DUAL-PLANE MONOPULSE AND ELECTRONIC SCAN IN ELEVATION, SUCH A RADAR COULD PROVIDE THE DATA RATE REQUIRED FOR WEAPON SUPPORT, SURFACE SEARCH, AND SHORT RANGE SURVEILLANCE. THE OBJECTIVE OF THIS PROJECT IS TO DESIGN AN ANTENNA WITH THIS CAPABILITY THAT IS ALSO LIGHTWEIGHT AND LOW COST. WITH ROW PHASE SHIFTERS, SLOTTEDWAVEGUIDE ARRAYS CAN ELECTRONICALLY SCAN IN ELEVATION AND PROVIDE MONOPULSE IN THAT PLANE. THEY ARE ALSO ATTRACTIVE BECAUSE OF THEIR LIGHTWEIGHT AND LOW COST COMPARED TO A FULLY PHASED ARRAY. HOWEVER, NO GOOD MEANS FOR OBTAINING AZIMUTH MONOPULSE PRESENTLY EXISTS. THE USUAL TECHNIQUE OF AZIMUTH BEAM SPLITTING ON MULTIPLE HITS IS NOT AN ACCEPTABLE ALTERNATIVE FOR THE PRESENT APPLICATION BECAUSE OF THE HIGH DATA RATE REQUIREMENTS. THE ANTENNA WE ARE PROPOSING PROVIDES THE NECESSARY DUAL-PLANE MONOPULSE CAPABILITY WHILE RETAINING THE BASIC SIMPLICITY OF A CONVENTIONAL WAVEGUIDE ARRAY. THE OBJECTIVE OF THIS PROJECT IS TO COMPLETE AN ANTENNA DESIGN WITH PREDICTIONS OF PERFORMANCE OVER THE OPERATING FREQUENCY BAND AND OVER ALL SCAN ANGLES.