AN/FPQ RADAR AUTOMATED PHASE TRACKING RECEIVER UPGRADE

MANY GOVERNMENT WEAPONS TESTING FACILITIES SUCH AS THE KWAJALEIN MISSILE RANGE DEPEND ON C BAND TRACKING RADARS SUCH AS THE AN/FPQ-19 TO PROVIDE ANGLE TRACKING AND RANGE DATA DURING MISSILE TESTS. THESE TYPES OF RADARS ARE STILL THE PRIMARY INSTRUMENTS USED FOR TEST SUPPORT, ALTHOUGH THE STATE OF THE ART HAS ADVANCED SINCE THESE RADARS WERE FIELDED. ONE LIMITATION OF THESE RADARS IS A CUMBERSOME TUNING AND CALIBRATION PROCEDURE WHEN THE FREQUENCY IS CHANGED MORE THAN 50 MHZ. THE LOCAL OSCILLATOR (LO) IS MECHANICALLY RETUNRED UNTIL THE AFC LOCKS ON, AND THE THREE RECEIVER CHANNELS ARE MANUALLY PHASE COMPENSATED. IN ORDER TO AVOID RECALIBRATION, TEST MISSILE BEACON TRANSPONDER FREQUENCIES HAVE TO BE LIMITED TO A 50 MHZ BAND SEGMENT. THE RADAR MAY BE UPGRADED BY AUTOMATING THESE ADJUSTMENTS SO THAT THE OPERATOR MAY TUNE THE RADAR RECEIVER FREQUENCY BY ADJUSTING A SINGLE CONTROL. THIS PROPOSAL DESCRIBES THE DESIGN AND PROCEDURE TO IMPLEMENT SUCH AN UPGRADE. THE PROPOSED IMPROVEMENT ENTAILS REPLACING THE RECEIVER LOCAL OSCILLATOR WITH A SOURCE THAT IS EASILY TUNED, AND PROVIDES DATA INDICATING THE TUNED FREQUENCY. A PROCESSOR SUBSYSTEM READS THE FREQUENCY DATA AND AUTOMATICALLY CONTROLS 360 DEGREE PHASE SHIFTERS THAT REPLACE THE MANUAL PHASE SHIFTERS IN THE RECEIVER.