Recently, dielectric devices, such as multi - layer ceramic capacitor (MLCC) prepared by BaTiO₃ (BT) based material (X7R property) have been miniaturized and used at high frequency. The high frequency dielectric measurement technique for microscopic region is useful for the designing and preparation of these dielectric devices. In experimental, the microwave reflection (r) intensity measurement using scanning non - contact state probe was carried out for measuring the dielectric distribution in the ferroelectric material and device. The dielectric measurement using non-resonant and contact probe was setup with an oscillator inserted a Gunn diode, directional coupler, detector (diode), coaxial tube and probe (6μmφ). The measurement frequency was changed from 9GHz to 11GHz using an oscillator. The r intensity was measured at room temperature as a function of distance between sample and probe. The sample was selected for BT single crystal and MLCC (cross - section). Dielectric mapping image obtained by r intensity minimum value, however image was not clear because of the noise insertion slightly to the image. Fourier transform (FT) analysis was hence carried out for reduce the noise insertion to the image as a function of space frequency. A two dimensional discrete FT was expressed as F(m₁,m₂)=(1/MN)ΣΣf(k₁, k₂)exp[-j2π(m₁k₁/M+m₂k₂/N)], where m₁, m₂ are discrete integers for x and y axes, and M and N are also discrete integers, and k₁, k₂ are space frequencies. From FT image, the noise was selected from raw data, and then inverse Fourier transformation (IFT) was carried out with filtering of the noise. As the result, noise reduction was carried out, and clear dielectric image was reconstructed by FT refinement.

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