The dielectric constant is a physical quantity that characterizes the dielectric properties of a material.With the use of microwave dielectrics in aircraft

ships

vehicles

communications

and other fields

the accurate measurement of dielectric constant has become a hot research topic.In order to improve the measurement accuracy of dielectric constant

a microwave non-destructive planar sensor loaded with hexagonal Complementary Split Ring Resonator（CSRR）is proposed.Comparing with the traditional quadrilateral CSRR microstrip resonator

the analysis results show that the hexagonal CSRR microstrip resonator has higher sensitivity than the quadrilateral CSRR

and the quality factor is also improved.Then

the interaction of the resonant frequency and the dielectric constant of the hexagonal CSRR microstrip resonator is studied.The simulation results show that when the dielectric constant of the measured sample becomes larger

the resonant frequency becomes smaller.The negative quadratic and the dielectric constant are linearly related.The analytical data of the dielectric constant and the resonant frequency are obtained by fitting the data of the simulation data

which are verified by measuring the resonant frequency of the sample when loading the measured sample.The proposed measurement method has important reference value in future engineering design.