| 摘 要： | In this paper,a new theory is developed for the analysis of real-time air-gap coupled SAWconvolvers.There are two important features about the theory proposed here.Firstly,we rigorouslyconsider the role of the surface states of semiconductors in acoustoelectric nonlinear interactions.Secondly,by means of a new equivalent circuit for such a convolver,we derive various new analyticalexpressions which describe the linear coupling coefficient for air-gap,nonlinear coupling coefficientfor acoustoelectric nonlinear interactions,and convolution output(or figure of merit);these expres-sions exhibit obvious dependence on bias.The frequency response of the surface states is also ana-lyzed. The theory presented here is a general formula applicable to dealing with the situation when thesemiconductor surface is accumulated,at flat-band,depleted,or inverted. The presented theory can essentially explain experimental results of SAW acoustoelectric non-linear interactions which were carried out by the author and others.
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