RF MODULE

3 In the Scalar Expressions dialog box, define the following variable:
VARIABLE NAME EXPRESSION
Z Z_tl*(1+S11_rfwh)/(1-S11_rfwh)
4 Click OK.
SOLVING THE MODEL
1 Open the Solver Parameters dialog box and select the Parametric solver.
2 Set the Parameter names to f and the Parameter values to
range(200e6,25e6,1.5e9), then click OK.
3 Click the Solve button on the Main toolbar.
POSTPROCESSING AND VISUALIZATION
To plot the antenna impedance as a function of frequency, do the following steps:
1 Open the Domain Plot Parameters dialog box.
2 On the General page, select all frequencies in the Solutions to use list.
3 Go to the Point page and select Point 1. Then enter real(Z) as Expression to plot
the radiation resistance.
4 Click the Line Settings button. From the Line style list, select Solid line. Click OK.
5 Click Apply to generate the resistance plot.
6 To generate a second plot in the same figure window, go to the General page and
select the Keep current plot check box.
7 Go to the Point page and enter imag(Z) as Expression to plot the reactance.
8 Click the Line Settings button. From the Line color list, select Color, then click the
Color button. Select a green color, then click OK. From the Line style list, select
Dashed line, then click OK to close the Line Settings dialog box.
9 On the General page, click the Title/Axis button. Enter Antenna impedance as Title
and Solid line: Real(Z); dashed line: Imag (Z) [\OMEGA] as Second axis
label. Click OK.
10 Click Apply to reproduce the plot in Figure 3-5.
To plot the radiation pattern as a function of frequency, follow these steps:
1 On the General page, select a few frequencies in the Solutions to use list, for example,
2e8, 8.632653e8, and 1.5e9.
76 | CHAPTER 3: RF AND MICROWAVE MODELS