[CST] Design of a T-junction _magic tee_ using CST Studio

EE316 Microwave Engineering

Experiment 2: Design of a T-junction magic tee using CST Studio

记录微波作业，从我做起????

Part 1: Introduction.

In this lab, we will still focus on the design of a magic tee model. But the simulation tool we use is changing to another software named CST Studio. We will still analyze several different cases of operating a Magic Tee and give a rectangular plot of S-parameter and a field overlay plot for each case.

**Part 2: Schematic & Model in this experiment. **

2.1 Schematic:

Schematic in this lab is shown in the Fig.1 below. There are 4 4 4 ports for this schematic:

• Port 1- Sum Port (" ∑ \sum ∑")

• Port 2- Co-linear

• Port 3 - Co-linear

• Port 4 - Difference Port (" Δ \Delta Δ")

  

Fig.1 Schenamtic consider in this lab

2.2 Model：

According to the given data, we can draw a model below:

Fig.2 Magic Tee Model

Part 3: Result & Analysis.

Since these four ports could all be used as inputs, there are 3 cases of operating a Magic Tee:

• Case 1: Set Port 1 (" ∑ \sum ∑") as a source.
• Case 2: Set Port 4 (" Δ \Delta Δ") as a source.
• Case 3: Set Port 2,3 as sources.

3.1 1-D result.

• Rectangular plot of S-parameters for this model:

Fig.3 Rectangular plot of S-paramters

• Reference impedance:

• Balance:

Fig.4 Reference Impedance

Fig.5 Balance

• More detailed 1-D result can be seen in the “1D result” folder.

3.2 Field Overlay Plot

• Input applied at Port 1:

Fig.6 Field Over Lay Plot with Input applied at Port 1

• Input applied at Port 2:

Fig.7 Field Over Lay Plot with Input applied at Port 2

• Input applied at Port 3:

Fig.8 Field Over Lay Plot with Input applied at Port 3

• Input applied at Port 4:

Fig.9 Field Over Lay Plot with Input applied at Port 4

Part 4: Analysis & Summary.

• If the input is applied at Port 1, the signal split equally to Ports 2 and 3, and no outputs come from Port 1;
• If the input is applied at Port 4, the signal split equally to Ports 2 and 3, and no outputs come from Port 4;
• If we apply inputs just at Port 2 or just at Port 3, the input would split to Ports 1 and 3;

Part 5: Experience.

• Using CST Studio to model is quite similar with ANSYS Electronics Desktop;
• Searching the Internet and textbook could help me learn more about the relative knowledge;