Measurement of the dielectric constant and loss tangent of materials in microwave frequency band using a rectangular waveguide cavity

Prof. M J Akhtar and Prof. K V Srivastava   

Procedure


Please download the files shown on the left to perform the actual experiment. It has a compressed folder containing one exe file and one folder named ASCII. The exe file is the LabView file that will run on Lab VIEW Run time Engine. Place the ASCII folder on your computer before running the exe file.

  • Step 1: Select the type of cavity either cylindrical cavity or rectangular cavity.

  • Step 2: Browse the ASCII folder on your computer.

  • Step 3: Now select the sample material for which you have to calculate the dielectric constant and the loss factor.

  • Step 4: Run the VI up to see the S21 vs frequency response for the empty cavity and the sample material chosen from the list of sample materials.

  • Step 5: Using the pertubation technique, the dielectric constant (ε'r), loss factor (ε"r) and the quality factor (Q) of the sample has been calculated.

  • Step 6: In case, you wish to see the dielectric constant (ε'r), loss factor (ε"r) and the quality factor (Q) of other sample materials then click stop and repeat steps 1,2,3 and 4 before running the program again.

  • You may see the the following example for your reference, where appropriate buttons are selected in order to measure the dielectric properties of Arlon AR600 material :

    Select the cavity crosssection


    Select the sample material


    View S2,1 vs frequency response for the empty cavity and the sample material chosen Arlon AR6OO.










    Now you can see the dielctric constant (ε'r), loss factor (ε"r) and the quality factor (Q) of the material Arlon AR6OO.