The perturbation of the dielectric resonator coupled to a microstrip line has been utilized to measure the perturber electrical parameters by means of the resonant frequency shift in the presence of the perturber. Two identical dielectric resonator oscillators operating at 4.25GHz are designed. One of the oscillator is perturbed with a sample. The shift in the oscillation frequency with respect to the reference oscillator is measured and used to determine the electrical properties of the sample.