Measurement of axial field distribution in a W-band extended interaction resonant cavity based on perturbation technique

The theoretical analysis and the experiment of perturbation techniques to the quantitative measurement of electric field characteristics in a 94 GHz extended interaction resonant cavity (EIRC) are described. Parameters such as the observed reflection coefficient (S11) and resonant frequency at the disturbance point can be adopted to determine the Q-factor, relative electric field intensity, and distribution of the EIRC. In the experiment stage, the frequency deviation characteristics of the tested EIRC under the influence of the metallic sphere are consistent with the simulation results, and the relative error of the frequency deviation is 4.40%. This provides an effective solution for studies of the performance monitoring of millimeter–submillimeter-wave electronic devices and the exploration of high-frequency material science.