The Impedance Field and Small-Signal Noise

1. Introduction

Small-signal electrical noise is inevitable and caused by random fluctuations in the processes inside the devices, such as microscopic variations in the carrier density caused by thermal fluctuations, and statistical variations in the recombination-generation rate.  Such noise can harm the intended behaviour of a circuit so it may be important to model the noise generated by devices.  And it may be interesting to know where in a device the noise is being generated so that lower noise devices can be designed.  Victory Device uses an impedance field method to calculate the noise.