Premium
Determination of dielectric properties of unknown substrates using hybrid approach
Author(s) -
Chung Kwok L.,
Guan Mengxin,
Cui Aiqi,
Feng Botao,
Li Yingsong,
Li Yansheng
Publication year - 2021
Publication title -
international journal of rf and microwave computer‐aided engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.335
H-Index - 39
eISSN - 1099-047X
pISSN - 1096-4290
DOI - 10.1002/mmce.22346
Subject(s) - dielectric , materials science , permittivity , microstrip , dissipation factor , relative permittivity , microwave , electrical impedance , dielectric spectroscopy , optoelectronics , electronic engineering , composite material , computer science , electrical engineering , telecommunications , chemistry , engineering , electrode , electrochemistry
Unknown dielectric properties of RF/microwave substrates cause headaches for microwave circuit and antenna designers. Most commercial reinforced dielectric substrates made from layers of woven‐glass and/or ceramic fillings lead to dielectric anisotropy. Often, re‐optimization and even re‐fabrication of designed prototypes are required when measuring results are found to be departed from the prediction. These are time consuming and costly. In order to determine the unknown complex permittivity of any substrates, this paper describes a hybrid approach composed of two measurement stages. The first stage is the coaxial‐probe method for predicting an initial complex permittivity of unknown dielectric substrates, which is known as the perpendicular permittivity. The second stage is the microstrip open‐circuit stub (OCS) method that regulates the complex permittivity of the dielectric laminate by mapping the input impedance curves of OCS via electromagnetic simulation and actual measurement. Three dielectric substrates without prior dielectric properties were selected to validate the proposed method. The equivalent dielectric constants, dissipation factors and dielectric anisotropies were determined and compared. The proposed method is found to be reliable for determining the unknown properties of dielectric substrates.