Error reduction processes using multiple measurements and numerical analysis for complex dielectric constant measurement with monostatic horn antenna

Abstract

To measure the complex dielectric constant of a material sample accurately by using the free-space reflection method using a monostatic horn antenna in the W-band, the authors of this paper have developed two processes to reduce errors and improve measurement accuracy. One of the improvement processes reduces errors caused by reflected millimeter-waves from surrounding objects. The process is carried out by averaging the reflection coefficients measured at multiple distances between the aperture of the antenna and the surface of the sample. The other improvement process reduces errors caused by the difference between the positions of the reference plane and the sample surface using numerical analysis. This paper presents overviews of our measurement setup for the complex dielectric constant and explains the two processes developed to reduce the measurement errors. The effectiveness of the developed processes is validated by measuring the complex dielectric constants of plastic plates. The result proves that the measurement errors can be reduced, and the complex dielectric constants of lossy plastic material can be measured accurately using the developed processes.