The progress in week 4

Fourth Lab Day

Details for 4th weeks's activities:

1. The first target of this week is to modifying the code of 'power divider calculator' interface. Our group has checked the input reflection calculated formulas with our supervisor based on corresponding codes, the error was finally founded and the interface performs correctly after the modification. The upgraded codes for the calculation of input reflection parts are shown below :
   
   The codes that has been modified are lighting on as the figure shown. After the debugging of codes,  we have tested the function of  power divider calculator with several groups of data. According to the experimental results, it shows that the calculator interface can be used to obtain correct graph of input reflection with different fundamental frequency and transmission lines' length for a four way power divider.  The tested results are shown below in series:

   

   Input reflection of 4 way power divider (Φx=0)

   

   Input reflection of 4 way power divider (Φx=π/2)

   

   Input reflection of 4 way power divider (Φx=π)

   

   Input reflection of 4 way power divider (Φx=3π/2)

   

   Input reflection of 4 way power divider (Φx=5π/2)

   It can be proved that all of this results are correct when compared with the theoretical graphs which have mentioned at week 2.  However, the power divider calculator that we designed is only applied for 4 way power divider. According to background knowledge, it has indicated that the calculation of input reflection for multiple ways power divider will be more complex as the grown of output amounts. Based on the limit of experiment period, our group decide only to complete this interface for 2-way and 4-way power divider. The work of 2-way power divider will be conducted at week 5. The second task for this week is to develop another interface which relative to the design of unequal power divider.
2. We have a group meeting that learned and discussed the knowledge of unequal power divider, which mainly focus on the fundamental field of 2-way unequal power divider. The model of 2 way unequal power divider with five different components are shown below:
   
   According to the figure above, it can be seen that the structure of 2 way unequal power divider is similar with equal power divider. However, the value of each component will be different in order to achieving different purpose of the unequal power divider, in details, it mostly depend on what value of power split ratio (Pa/Pb) customer want. The corresponding calculation for each component are listed below, which can be used for the coding of interface of unequal power divider:
   
   Based on the fundamental learning of unequal power divider,  we decided to coding a interface of unequal power divider which can be used for any customer who want to design an unequal power divider. With the help of this interface, company do not needs to understand the detailed knowledge of the calculation for unequal power divider. The only thing they need to do is inputting the value of power split ratio, then the interface can calculate all designed value for each component automatic.
3. The detailed processes that to complete the unequal power divider designer including three stages. First of all, we crated a simply 'matlab' function codes that used to calculated each component's value based on the given formulas. The codes are shown below:
   
   
   The codes that are light on is the linking component between the codes of interface and and calculated function codes. It is also the most difficult part for the coding of this interface is how to linking the outputs of calculated function with the static text at interface. In simply words, the hardest working is how to make the interface outputs display correct results. Thirdly, the interface named "unequal power divider designer" was generated by simulating corresponding codes. There are two inputs with five outputs in the interface, user can edit the designed value of input impedance for power divider and the value of power split ratio, the corresponding designed value of each component will be displayed in the output respectively followed by click the push button 'calculate'. We have tested the interface for two groups of data, the results are indicted correct and are shown below: 

   

   power divider with power split ratio equals 1

   
   

   

   power divider with power split ratio equals 2

4. The project named automatic design of power divider has nearly completed two calculation interface before week 5.  Our group will complete their performance respective at nest week, meanwhile, we will have a conclusion for this project based on varies of parts. 

Summary of 4th week's activities:

• Completing the debugging of the power divider calculator interface, modifies its calculation for a four way Wikinson power divider.
• Learning the knowledge of unequal power divider and discussion the interface of unequal power divider designer for a 2 way Wikinson power divider 
• Designed and completed the interface of unequal power divider by using Matlab "GUI" function.