Correlator with a modified optical Rayleigh interferometer system used to measure small phase shifts of rf signals

An experimental investigation was made of the operation, and estimates were obtained of the characteristics, of a correlator based on a double-beam optical Rayleigh interferometer with a doubled acousto-optical cell. This correlator was used to measure small phase shifts of radar signals. The experimental results were compared with a theoretical analysis of the correlator operation. The precision deduced from measurements reached 0.003 rad for the phase shift and 0.005 ns for the time delay. The theoretical analysis and the experimental results showed that the proposed and implemented interferometric correlator is quite promising for radar systems.