Interference of Two Co-Generated Frequency Modulated Parametric Array Signals
S.Li, J.Wang (Shanghai Acoustics Lab., Acdemia Sinica, Shanghai, China)
Some interferential effects of two co-generated modulated parametric array signals are studied. These effects include the interference of the output of the matchfilters of the difference frequency signals of two parametric arrays generated simultaneously by the same transducer. a) One of the two parametric arrays is forward linear frequency modulated; the other is backward linear frequency modulated, and the central frequencies of the modulating signals for the two parametric arrays are the same; b) both of the two parametric arrays are forward linear frequency modulated, but the central frequencies of modulating signals for the two parametric arrays are different but quiet near. Simulation results as well as results of experiment in water and in sand show that in both situations the interference is tolerable in engineering.
Section : 11