I'm a student working with linear two ports and we have begun to linearize them; we are working on small signal problems, where linearization yields a matrix which linearly describes the two-port at some operating point. Once we have solved for a linearized descriptive matrix, we are tasked with generating a replacement circuit diagram, one for the 'big' signal, and one for the 'small' signal. All this truly means is creating a circuit where we reference everything, all voltages and currents (big signal) and one where we only focus on our deltas (small signal). I'm ultimately still very confused about how this works and why we do it etc. More than anything, I'm looking for someone who can provide me some sources or more information regarding this topic—in the context of both two ports and one ports.

All help is appreciated!

 

I'm a student working with linear two ports and we have begun to linearize them; we are working on small signal problems, where linearization yields a matrix which linearly describes the two-port at some operating point. Once we have solved for a linearized descriptive matrix, we are tasked with generating a replacement circuit diagram, one for the 'big' signal, and one for the 'small' signal. All this truly means is creating a circuit where we reference everything, all voltages and currents (big signal) and one where we only focus on our deltas (small signal). I'm ultimately still very confused about how this works and why we do it etc. More than anything, I'm looking for someone who can provide me some sources or more information regarding this topic—in the context of both two ports and one ports.

All help is appreciated!

In many cases, we use the large signal models for biasing or for, you guessed it, large signals.
The small signal model is usually used for AC analysis, where smaller quantities vary around the larger quantities.

Example:
Large signal: we bias an output at 5vdc.
Small signal: the output varies 0.1vac riding on that 5vdc.
Large signal: the output varies 2vac riding on that 5vdc.