Based free-space microwave measurement system (FMMS) for permittivity determination of plain water approach at 18 GHz to 26 GHz frequency range (K band) / Nurul Huda Shakila Zulkipli

Free-space microwave measurement system (FMMS) using microwave nondestructive testing (MNDT) method involves measurement of reflection (S11) and transmission (S21) coefficients in free-space. MNDT is a method that determining the material characteristics without permanently changing its properties. The main objective of this project is to characterize the complex permittivity, loss factor and loss tangent of three types or samples of plain water which are piped water, reverse-osmosis (RO) water and mineral water. The samples were measured by using FMMS equipment via the method of MNDT at frequency 18 GHz to 26 GHz (K band). In order to measure all the characteristics, the reflection (S11) and transmission (S21) coefficients parameters was executed using FORTRAN software. The results are obtained in the range of frequency 19.18 GHz - 25.9 GHz only. From the result obtained, the mineral water show the average highest measured of complex permittivity than the piped and RO water which is close to the measured reported data complex permittivity of 80 at 20°C [7]. For the three types of plain water, the difference in complex permittivity can be observed at higher frequency.