LAUSR

A novel method for measuring the dielectric constant and loss tangent of dielectric substrates is presented in this article. Four resonant modes of the rectangular resonant cavity, TE101, TE105, TE109, and TE1015, are utilized to realize the multiband measurement from 0.9 to 10 GHz. The introduction of additional slots cuts down the quality factor of some miscellaneous modes, making the working modes more obvious and convenient for extraction. Based on the traditional perturbation formulas, considering the sinusoidal field distribution in the sample, modified formulas are deduced to obtain more accurate results. An experimental resonant cavity is fabricated and measured to demonstrate the effectivity of the proposed method.