An analysis of dielectric constant of pharmaceutical medicines using microwave radiation exposure

The analysis of dielectric constant of pharmaceutical medicines at microwave frequency is presented in this paper. The dielectric constant also known as the permittivity was measured by using open-ended coaxial probe technique over the microwave frequency range from 400Mhz to 4GHz. The samples of two pharmaceutical medicines were prepared at different moisture content (5ml, 10ml, 15ml, 20ml, 25ml and 30ml). A Vector Network Analyzer (VNA) was used to record the data of dielectric constant e' and dielectric loss e" of these four sample. The dielectric constant of pharmaceutical medicines samples decreased with the increase of the frequency. On the other hand, the dielectric loss of these samples increased when frequency increased. Both of dielectric constant and dielectric loss of pharmaceutical samples increased with increasing moisture content from 5ml to 30ml.