Metallic Cover over Wilkinson Power Divider
The Wilkinson power divider is a rather simple microwave circuit that allows equal splitting the input power to two of the identical output ports. The EM simulation carried out in the WIPL-D Pro 3D EM solver is itself simple, regardless the high operating frequency of 25 GHz and extremely thin substrate (0.005 mm with Er=3).
The application note demonstrates the most efficient way to model microstrip ports using two trapezoidal plates with a short/thin wire in between. Both wire ends are connected to metallic quads via triple junctions, which instructs the kernel to consider all three nodes to be in electrical connection. Such feeding mechanism inherently enables very low reflection loss. The lumped resistor is realized via concentrated loading.
A metallic box is added to the model of the divider to decrease EM coupling with neighboring devices. The performance of the divider with and without the box is compared. The results are as expected: very low return loss for microstrip ports, equal power division (-3 dB) between the input and the outputs, very good isolation between the output ports and rather low influence of adding the metallic cover.
Section: Microwave Circuits
For full version of the document, please check the following pdf.