design structure of substrate integrated waveguides( SIW)
and the sensitive region is constructed utilizing electromagnetic band gap structure
and cavity perturbation method is used to analyze. According to the principle of the frequency shift due to the effect of humidity on dielectric constant
the resonator frequency and the signal amplitude of resonator are measured. The test results show that the humidity range of resonator designed by SIW is11 %
97 % RH and the sensitivy characteristics is 13. 37
46. 52 k Hz/RH. The new microwave component has good research significance and measurement result.