AN 8-BIT 2 GHZ INTEGRATING ANALOG-TO-DIGITAL CONVERTER FOR COHERENT-ON-RECEIVE UWB (ULTRAWIDE BANDWIDTH) RADAR

RADAR DETECTION OF WEAK TARGETS IN THE PRESENCE OF A HIGH LEVEL OF CLUTTER NECESSITATES AN ULTRA WIDE BANDWIDTH ANALOG-TO-DIGITAL CONVERTER (ADC) WITH SUFFICIENT RESOLUTION. THIS PROPOSAL PRESENTS A TECHNICAL APPROACH AND SYSTEM ARCHITECTURE FOR AN 8-BIT, 2 GHZ FULL SCALE BANDWIDTH INTEGRATING ADC TO SATISFY THIS NEED. ADDITIONALLY, THE ADC WILL BE DRIVEN BY A CLOCK SIGNAL WHICH CAN BE SYNCHRONIZED TO A TRIGGER PULSE WITH A RESOLUTION OF +/0.5 PICOSECOND. SUCH AN ADC WOULD FACILITATE THE DEVELOPMENT OF A COHERENTON-RECEIVER UWB (ULTRA WIDE BANDWIDTH) RADAR RECEIVERS. WHAT IS PROPOSED IS A "FLASH"ADC ARCHITECTURE, WITH FAST ACT (ACOUSTIC CHARGE TRANSPORT) SAMPLERS ON THE FRONT-END, AND SLOWER, COMMERCIALLY AVAILABLE 8-BIT ADCS ON THE BACK-END. TWO EMBODIEMENTS ARE DESCRIBED.ONE NECESSITATES USING THE ACT DEVICE AS A SERIAL OF PARALLEL CONVERTER IN ADDITION TO A SAMPLER AND REALIZES 8 BITS OF ADC SYSTEM RESOLUTION. THE OTHER DOES NOT REQUIRE ANY SERIAL TO PARALLEL SHIFTING BUT ACHIEVES ONLY 6 BITS OF RESOLUTION.