Wilkinson Power Divider
XF7, XFdtd | tagged Microwave Circuits Request project files for this example by clicking here.
The stripline portion of a Wilkinson Power Divider is loaded into XF7 from a CAD file. The distance between the receive ports is 19.94 mm and the distance from the source to the far conductor is 15.57 mm. A substrate is created with a permittivity of 2.94, thickness of 1.524 mm, and the stripline conductor is located in the middle. Also, a 100 ohm isolation resistor is added as a lossy dielectric. Figure 1 shows the structure of the power divider.
Figure 1
Layout including substrate, isolation resistor, and stripline.
As in any FDTD simulation, the accuracy of the results is dependent on how well the grid matches the CAD model. The gridding properties of the stripline are set so grid lines automatically align with its edges and XACT Accurate Cell Technology is enabled for the diagonal portions so the errors due to staircasing are reduced. Figure 2 shows the resultant mesh in the plane of the stripline.
Figure 2
Mesh representation of the power divider with automatic gridding and XACT enabled.
A broadband simulation is run with the upper and lower Z boundaries set to PEC. Upon completion, S-Parameters are loaded for the three ports. Figure 3 shows a wide band of operation for this power divider. Steady state surface currents are also computed at 8.8 GHz, as seen in Figure 4.
Figure 3
S-Parameter results for the three ports.
Figure 4
Steady state surface currents on the stripline at 8.8 GHz.
