Abstract: A new phenomenon,that the focusing axis of SAW excited by an array of IDTs the centre positions of which are arranged according to a chirp law and the synchronous frequencies are designed with another related chirp law,translates,instead of rotates,with the frequency of the input signal,is predicted from theoretical analysis and verified by experiments.Based on this phenomenon,a new configuration of integrated acoustic RF spectrum analyzer (IASA) is proposed.In this configuration,troubles caused by the anisotropy of the substrate can be avoided or reduced by virtue of the paralel translation scanning behavior.Contrarily,in other configurations of IASA,the same trouble can not be overcome because of the deflection scanning fashion.This phenomenon discovered in our laboratory may,therefore,induce a significant progress for realizing a practical IASA.