gm/id of transistor in matlab

To find the gm/id of a transistor in Matlab, we need to perform simulation and modeling. The following are the steps to find gm/id:

1. Define the transistor model: We need to define the transistor model in Matlab. We can use either the standard MOSFET models like BSIM or a custom model.

2. Define the simulation environment: We need to define the simulation environment like the DC bias points, temperature, and process parameters.

3. Run the simulation: Using the transistor model and simulation environment, we need to run the simulation.

4. Calculate the gm/id: After the simulation finishes, we can calculate the gm/id ratio by dividing the transconductance (gm) by the drain current (id).

Here is an example code block that demonstrates how to find the gm/id ratio of a transistor in Matlab using the BSIM model:

main.m
% Define the transistor model
model = load('bsim3v3.mod');
simulator = ncmos(model);

% Define the simulation environment
simulator.Tem = 25; % Temperature in Celsius
simulator.Vd = 1.2; % Drain voltage
simulator.Vg = 0:0.01:1.0; % Gate voltage sweep
simulator.Vs = 0; % Source voltage
simulator.Rs = 0; % Source resistance
simulator.Rd = 10e3; % Drain resistance

% Run the simulation
results = simulate(simulator);

% Calculate the gm/id ratio
gm = results.gm;
id = results.id;
gm_over_id = gm./id;

% Plot the results
plot(simulator.Vg, gm_over_id);
xlabel('Gate voltage (V)');
ylabel('gm/id');
598 chars
25 lines

This code calculates the gm/id ratio for a n-channel MOSFET using BSIM model for a range of gate voltages, and then plots the gm/id ratio as a function of gate voltage.