The effect of geometry on the current transfer and noise figure of alloy-type transistors

Normal small-signal and white-noise analyses of transistors are based on a one-dimensional model. The results are applicable to practical transistors in which there is symmetry about the emitter-collector axis. When there is not axial symmetry the current transfer and noise may be changed considerably. In particular, it is found that excess noise is generated: this is thought to be a surface phenomenon. Experimental results are presented for actual transistors with and without axial symmetry.