Global Features. Gain modification
As was mentioned at the beginning of the guide, it is possible to assign value to components using global variables. Let's study how to work with them.
In order to use global variables, declare them as follows:
Create a text frame;
In the text frame, declare the command .nsx - the beginning of the enumeration for the simulator;
After command .nsx it is necessary to declare command .param - it is the beginning of global variables declaration;
Then global variables are enumerated with "+" before each of them.
Below is an image that shows all of the above (note the values of the circuit electronic components):
The values Re, Rk, Rl, Rh are also global variables. They must be used in the circuit as values.
Note: You can write complex mathematical dependencies when declaring global variables. They allow you to get a series of expressions that depend on the enumeration, not just values of electronic components, but global variables.
Now let's run Sweep Parameter of Ku values from 1 to 10 and run the calculation.
We see a series of gains with a given step. As the gain increases, the discrepancy between the calculated dependencies and the actual ones increases due to the non-ideality of the transistor used in the circuit.
Let's see what is going on in the time domain:
You can see how the amplitude of the output signal is increasing at the circuit output, with each time the operating point is corrected, recalculated according to the dependencies described in the nsx block using global variables.
