RF MODULE

5 Click the Line Settings button. Make sure that Line color and Line style are set to cycle,
then click OK to close the Line Settings dialog box.
6 Click OK to generate the plot in Figure 3-7.
Transient Analysis with External Circuit
To add an external circuit, it is necessary to first change the analysis type to transient
analysis. Then you add the circuit using the SPICE circuit editor.
OPTIONS AND SETTINGS
1 From the Physics menu, choose Properties.
2 In the Application Mode Properties dialog box, select Transient propagation from the
Analysis type list.
3 Click OK.
PHYSICS SETTINGS
1 From the Physics menu, choose Boundary Settings.
2 Select Boundary 6, and choose the Circuit port boundary condition from the
Boundary Condition list.
3 Click OK.
4 From the Physics menu, choose SPICE Circuit Editor.
5 In the SPICE Circuit Editor dialog box, enter the following netlist in the SPICE netlist
area.
V1 1 0 SIN 0 100 1.5GHz
R1 1 2 50
X1 2 0 conical
.SUBCKT conical 1 COMSOL: *
.ENDS
6 Click OK.
SOLVING THE MODEL
1 From the Solve menu, open the Solver Parameters dialog box.
2 Type 0 3e-9 in the Times edit field.
3 Go to the Time Stepping page, choose Time steps from solver from the Times to store
in output list, and Manual from the Time steps taken by solver list.
4 Type 1/15e9 in the Time step edit field.
5 Click OK.
78 | CHAPTER 3: RF AND MICROWAVE MODELS