檢視 $drainbias 的原始碼

To determine the bias added to the drain contact. 
It should be written in one row with three numbers which represent the start of the bias voltage the end of the bias voltage and the step size of the voltage in sequence. 
For example: <br>

 $drainbias 
 -0.3 0.3 0.1 

This means that the bias of the gate contact will starts at 0V and increases 0.1V every step until the gate bias reached 0.4V. <br>
i.e. -0.3 -0.2 -0.1 0 0.1 0.2 0.3

<br>
This one is similar to gate bias. If the simulation arranges different gate biases and different drain biases, it will
run drain bias and then gate bias. The loop is 

 do vg = vgstart to vgend  by vgstep
   do vd=vdstart to vdend by vdstep
       Run
    end do
 end do