Measurement of Multiband Complex Permittivity by Multi-Point Method

In this paper, a single cylinder resonator is proposed to achieve broadband multiband dielectric constant and loss tangent measurements from 0.9-6.5 GHz through multiple working modes. The resonant cavity size and appropriate modes are selected according to the formula for resonant frequency, and TM<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">010</inf>, TM<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">030</inf>, TM<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">050</inf> and TM<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">060</inf> are finally determined as the working modes of the resonator. Accurate advancement of the quality factor for multiple modes by the multi-point method further improves the accuracy of the calculation of the loss tangent. Finally, simulations and measurements were carried out on three stable Rogers dielectric substrates, and good measurement results were obtained.