Measurement of dielectric constant of distilled water by a developed apparatus at 90GHz

The dielectric constant of distilled water (DW) was measured using a Gunn oscillator at the frequency 90.05GHz as a power source. The system of spectrometer is a simple W-band type homodyne which consists of magic-T, attenuator, phase shifter, and a specially designed sample reflector. The sampling portion of the apparatus was newly designed in order to measure fluid dielectrics. Two experimental methods for determining the dielectric constant of DW was used. These results showed the dielectric constant of DW at 90Hz was estimated to be 11.5