/spl beta/-driven threshold elements

Circuits on threshold elements have aroused considerable interest in recent years. One of the possible approaches of their implementation is using output wired CMOS inverters. The model of such an element is a CMOS pair with variable /spl beta/ of fully open p- and n-transistors. This model is specified by the ratio form of threshold function. It has been proved that any threshold function can be rewritten in ratio form. This gives us an evident way of /spl beta/-driven implementation of threshold functions. It has the following differences from implementation on output wired CMOS invertors: -/spl beta/DTE requires one transistor per weight unit rather than two; -the implementability of /spl beta/DTE depends only on threshold value, not on the input weights sum. The analysis of /spl beta/DTE implementability, examples of circuits and results of their SPICE simulation are given.